diff --git a/addons/bus/static/src/js/crosstab_bus.js b/addons/bus/static/src/js/crosstab_bus.js
index c0402dcac10..13e6cdb98cc 100644
--- a/addons/bus/static/src/js/crosstab_bus.js
+++ b/addons/bus/static/src/js/crosstab_bus.js
@@ -2,7 +2,6 @@ odoo.define('bus.CrossTab', function (require) {
 "use strict";
 
 var Longpolling = require('bus.Longpolling');
-var session = require('web.session');
 
 
 /**
diff --git a/addons/im_livechat/static/src/js/im_livechat.js b/addons/im_livechat/static/src/js/im_livechat.js
index 3179986e88a..2a637f4b7d6 100644
--- a/addons/im_livechat/static/src/js/im_livechat.js
+++ b/addons/im_livechat/static/src/js/im_livechat.js
@@ -44,6 +44,12 @@ if (!_.contains(urlHistory, page)) {
 
 var LivechatButton = Widget.extend({
     className:'openerp o_livechat_button d-print-none',
+    custom_events: {
+        'close_chat_window': '_onCloseChatWindow',
+        'post_message_chat_window': '_onPostMessageChatWindow',
+        'save_chat_window': '_onSaveChatWindow',
+        'updated_unread_counter': '_onUpdatedUnreadCounter',
+    },
     events: {
         'click': '_openChat'
     },
@@ -112,7 +118,7 @@ var LivechatButton = Widget.extend({
      * @param {Object} [options={}]
      */
     _addMessage: function (data, options) {
-        options = _.extend({}, options, {
+        options = _.extend({}, this.options, options, {
             serverURL: this._serverURL,
         });
         var message = new WebsiteLivechatMessage(this, data, options);
@@ -130,7 +136,7 @@ var LivechatButton = Widget.extend({
         this._chatWindow.$('.o_thread_composer input').prop('disabled', true);
 
         var feedback = new Feedback(this, this._livechat);
-        feedback.replace(this._chatWindow.threadWidget.$el);
+        this._chatWindow.replaceContentWith(feedback);
 
         feedback.on('send_message', this, this._sendMessage);
         feedback.on('feedback_sent', this, this._closeChat);
@@ -159,7 +165,7 @@ var LivechatButton = Widget.extend({
             } else { // normal message
                 this._addMessage(notification[1]);
                 this._renderMessages();
-                if (this._chatWindow.isFolded() || !this._chatWindow.threadWidget.isAtBottom()) {
+                if (this._chatWindow.isFolded() || !this._chatWindow.isAtBottom()) {
                     this._livechat.incrementUnreadCounter();
                 }
             }
@@ -204,13 +210,16 @@ var LivechatButton = Widget.extend({
             if (!livechatData || !livechatData.operator_pid) {
                 alert(_t("None of our collaborators seems to be available, please try again later."));
             } else {
-                self._livechat = new WebsiteLivechat(livechatData);
+                self._livechat = new WebsiteLivechat({
+                    parent: self,
+                    data: livechatData
+                });
                 self._openChatWindow();
                 self._sendWelcomeMessage();
                 self._renderMessages();
 
-                self.busBus.addChannel(self._livechat.getUUID());
-                self.busBus.startPolling();
+                self.call('bus_service', 'addChannel', self._livechat.getUUID());
+                self.call('bus_service', 'startPolling');
 
                 utils.set_cookie('im_livechat_session', JSON.stringify(self._livechat.toData()), 60*60);
                 utils.set_cookie('im_livechat_auto_popup', JSON.stringify(false), 60*60);
@@ -235,41 +244,16 @@ var LivechatButton = Widget.extend({
             self._chatWindow.$el.css(cssProps);
             self.$el.hide();
         });
-        this._chatWindow.on('close', this, function () {
-            var input_disabled = this._chatWindow.$('.o_thread_composer input').prop('disabled');
-            var ask_fb = !input_disabled && _.find(this._messages, function (message) {
-                return message.getID() !== '_welcome';
-            });
-            if (ask_fb) {
-                this._chatWindow.toggleFold(false);
-                this._askFeedback();
-            } else {
-                this._closeChat();
-            }
-        });
-        this._chatWindow.on('post_message', this, function (message) {
-            self._sendMessage(message).fail(function (error, e) {
-                e.preventDefault();
-                return self._sendMessage(message); // try again just in case
-            });
-        });
-        this._chatWindow.on('save_chat', this, this._onSaveChat);
-        this._chatWindow.threadWidget.$el.on('scroll', null, _.debounce(function () {
-            if (self._chatWindow.threadWidget.isAtBottom()) {
-                self._livechat.resetUnreadCounter();
-                self._chatWindow.renderHeader();
-            }
-        }, 100));
     },
     /**
      * @private
      */
     _renderMessages: function () {
-        var shouldScroll = !this._chatWindow.isFolded() && this._chatWindow.threadWidget.isAtBottom();
+        var shouldScroll = !this._chatWindow.isFolded() && this._chatWindow.isAtBottom();
         this._livechat.setMessages(this._messages);
         this._chatWindow.render();
         if (shouldScroll) {
-            this._chatWindow.threadWidget.scrollToBottom();
+            this._chatWindow.scrollToBottom();
         }
     },
     /**
@@ -282,7 +266,7 @@ var LivechatButton = Widget.extend({
         return session
             .rpc('/mail/chat_post', {uuid: this._livechat.getUUID(), message_content: message.content})
             .then(function () {
-                self._chatWindow.threadWidget.scrollToBottom();
+                self._chatWindow.scrollToBottom();
             });
     },
     /**
@@ -306,6 +290,23 @@ var LivechatButton = Widget.extend({
     // Handlers
     //--------------------------------------------------------------------------
 
+    /**
+     * @private
+     * @param {OdooEvent} ev
+     */
+    _onCloseChatWindow: function (ev) {
+        ev.stopPropagation();
+        var isComposerDisabled = this._chatWindow.$('.o_thread_composer input').prop('disabled');
+        var shouldAskFeedback = !isComposerDisabled && _.find(this._messages, function (message) {
+            return message.getID() !== '_welcome';
+        });
+        if (shouldAskFeedback) {
+            this._chatWindow.toggleFold(false);
+            this._askFeedback();
+        } else {
+            this._closeChat();
+        }
+    },
     /**
      * @private
      * @param {Array[]} notifications
@@ -318,10 +319,34 @@ var LivechatButton = Widget.extend({
     },
     /**
      * @private
+     * @param {OdooEvent} ev
+     * @param {Object} ev.data.messageData
      */
-    _onSaveChat: function () {
+    _onPostMessageChatWindow: function (ev) {
+        ev.stopPropagation();
+        var self = this;
+        var messageData = ev.data.messageData;
+        this._sendMessage(messageData).fail(function (error, e) {
+            e.preventDefault();
+            return self._sendMessage(messageData); // try again just in case
+        });
+    },
+    /**
+     * @private
+     * @param {OdooEvent} ev
+     */
+    _onSaveChatWindow: function (ev) {
+        ev.stopPropagation();
         utils.set_cookie('im_livechat_session', JSON.stringify(this._livechat.toData()), 60*60);
     },
+    /**
+     * @private
+     * @param {OdooEvent} ev
+     */
+    _onUpdatedUnreadCounter: function (ev) {
+        ev.stopPropagation();
+        this._chatWindow.renderHeader();
+    },
 });
 
 /*
diff --git a/addons/im_livechat/static/src/js/models/website_livechat.js b/addons/im_livechat/static/src/js/models/website_livechat.js
index a21f2ee2f49..758f90b302c 100644
--- a/addons/im_livechat/static/src/js/models/website_livechat.js
+++ b/addons/im_livechat/static/src/js/models/website_livechat.js
@@ -3,6 +3,8 @@ odoo.define('im_livechat.model.WebsiteLivechat', function (require) {
 
 var AbstractThread = require('mail.model.AbstractThread');
 
+var session = require('web.session');
+
 /**
  * Thread model that represents a livechat on the website-side. This livechat
  * is not linked to the mail service.
@@ -12,34 +14,37 @@ var WebsiteLivechat = AbstractThread.extend({
     /**
      * @override
      * @private
-     * @param {Object} livechatData
-     * @param {boolean} [livechatData.folded] states whether the livechat is
+     * @param {Object} params
+     * @param {Object} params.data
+     * @param {string} params.data.anonymous_name
+     * @param {boolean} [params.data.folded] states whether the livechat is
      *   folded or not. It is considered only if this is defined and it is a
      *   boolean.
-     * @param {integer} livechatData.id the ID of this livechat.
-     * @param {integer} [livechatData.message_unread_counter] the
-     *   unread counter of this livechat.
-     * @param {Array} livechatData.operator_pid
-     * @param {string} livechatData.name the name of this livechat.
-     * @param {string} [livechatData.state] if 'folded', the livechat is folded.
+     * @param {integer} params.data.id the ID of this livechat.
+     * @param {integer} [params.data.message_unread_counter] the unread counter
+     *   of this livechat.
+     * @param {Array} params.data.operator_pid
+     * @param {string} params.data.name the name of this livechat.
+     * @param {string} [params.data.state] if 'folded', the livechat is folded.
      *   This is ignored if `folded` is provided and is a boolean value.
-     * @param {string} livechatData.uuid the UUID of this livechat.
+     * @param {string} params.data.uuid the UUID of this livechat.
+     * @param {im_livechat.im_livechat.LivechatButton} params.parent
      */
-    init: function (livechatData) {
-        var params = { data: livechatData };
-        this._super.call(this, params);
+    init: function (params) {
+        this._super.apply(this, arguments);
 
-        this._operatorPID = livechatData.operator_pid;
-        this._uuid = livechatData.uuid;
+        this._members = [];
+        this._operatorPID = params.data.operator_pid;
+        this._uuid = params.data.uuid;
 
-        if (livechatData.message_unread_counter !== undefined) {
-            this._unreadCounter = livechatData.message_unread_counter;
+        if (params.data.message_unread_counter !== undefined) {
+            this._unreadCounter = params.data.message_unread_counter;
         }
 
-        if (_.isBoolean(livechatData.folded)) {
-            this._folded = livechatData.folded;
+        if (_.isBoolean(params.data.folded)) {
+            this._folded = params.data.folded;
         } else {
-            this._folded = livechatData.state === 'folded';
+            this._folded = params.data.state === 'folded';
         }
     },
 
@@ -66,6 +71,16 @@ var WebsiteLivechat = AbstractThread.extend({
     getUUID: function () {
         return this._uuid;
     },
+    /**
+     * Increments the unread counter of this livechat by 1 unit.
+     *
+     * Note: this public method makes sense because the management of messages
+     * for website livechat is external. This method should be dropped when
+     * this class handles messages by itself.
+     */
+    incrementUnreadCounter: function () {
+        this._incrementUnreadCounter();
+    },
     /**
      * AKU: hack for the moment
      *
@@ -87,6 +102,20 @@ var WebsiteLivechat = AbstractThread.extend({
             uuid: this.getUUID(),
         };
     },
+
+    //--------------------------------------------------------------------------
+    // Private
+    //--------------------------------------------------------------------------
+
+    /**
+     * Warn that the unread counter has been updated on this livechat
+     *
+     * @override
+     * @private
+     */
+    _warnUpdatedUnreadCounter: function () {
+        this.trigger_up('updated_unread_counter');
+    },
 });
 
 return WebsiteLivechat;
diff --git a/addons/im_livechat/static/src/js/models/website_livechat_message.js b/addons/im_livechat/static/src/js/models/website_livechat_message.js
index f8854ba7655..9728c78e270 100644
--- a/addons/im_livechat/static/src/js/models/website_livechat_message.js
+++ b/addons/im_livechat/static/src/js/models/website_livechat_message.js
@@ -13,7 +13,7 @@ var AbstractMessage = require('mail.model.AbstractMessage');
 var WebsiteLivechatMessage =  AbstractMessage.extend({
 
     /**
-     * @param {Widget} parent
+     * @param {im_livechat.im_livechat.LivechatButton} parent
      * @param {Object} data
      * @param {Object} options
      * @param {string} options.serverURL
diff --git a/addons/im_livechat/static/src/js/website_livechat_window.js b/addons/im_livechat/static/src/js/website_livechat_window.js
index 4e34be60557..ea5b11f5417 100644
--- a/addons/im_livechat/static/src/js/website_livechat_window.js
+++ b/addons/im_livechat/static/src/js/website_livechat_window.js
@@ -11,7 +11,7 @@ var AbstractThreadWindow = require('mail.AbstractThreadWindow');
 var LivechatWindow = AbstractThreadWindow.extend({
     /**
      * @override
-     * @param parent
+     * @param {im_livechat.im_livechat.LivechatButton} parent
      * @param {im_livechat.model.WebsiteLivechat} thread
      */
     init: function (parent, thread) {
@@ -28,7 +28,15 @@ var LivechatWindow = AbstractThreadWindow.extend({
      * @override
      */
     close: function () {
-        this.trigger('close');
+        this.trigger_up('close_chat_window');
+    },
+    /**
+     * Replace the thread content with provided new content
+     *
+     * @param {$.Element} $element
+     */
+    replaceContentWith: function ($element) {
+        $element.replace(this._threadWidget.$el);
     },
     /**
      * Warn the parent widget (LivechatButton)
@@ -38,7 +46,7 @@ var LivechatWindow = AbstractThreadWindow.extend({
      */
     toggleFold: function () {
         this._super.apply(this, arguments);
-        this.trigger('save_chat');
+        this.trigger_up('save_chat_window');
         this.updateVisualFoldState();
     },
 
@@ -52,7 +60,8 @@ var LivechatWindow = AbstractThreadWindow.extend({
      * @param {Object} messageData
      */
     _postMessage: function (messageData) {
-        this.trigger('post_message', messageData);
+        this.trigger_up('post_message_chat_window', { messageData: messageData });
+        this._super.apply(this, arguments);
     },
 });
 
diff --git a/addons/im_support/static/src/js/mail_manager.js b/addons/im_support/static/src/js/mail_manager.js
index 193f78d692b..6a44e87ed8d 100644
--- a/addons/im_support/static/src/js/mail_manager.js
+++ b/addons/im_support/static/src/js/mail_manager.js
@@ -186,7 +186,10 @@ MailManager.include({
      * @override
      */
     _makeMessage: function (data) {
-        if (_.contains(data.channel_ids, this.supportChannelUUID)) {
+        if (
+            this.supportChannelUUID &&
+            _.contains(data.channel_ids, this.supportChannelUUID)
+        ) {
             return new SupportMessage(this, data, this._emojis);
         }
         return this._super.apply(this, arguments);
@@ -239,10 +242,10 @@ MailManager.include({
                 // ignore history requests
                 return;
             }
-            var message = _.extend(notification[1], {
+            var messageData = _.extend(notification[1], {
                 channel_ids: [self.supportChannelUUID],
             });
-            self._handleChannelNotification(message);
+            self._handleChannelNotification({ data: messageData });
         });
     },
 });
diff --git a/addons/im_support/static/src/js/support_channel.js b/addons/im_support/static/src/js/support_channel.js
index 4fd66bdfc81..3147cc55a94 100644
--- a/addons/im_support/static/src/js/support_channel.js
+++ b/addons/im_support/static/src/js/support_channel.js
@@ -3,7 +3,7 @@ odoo.define('im_support.SupportChannel', function (require) {
 
 var supportSession = require('im_support.SupportSession');
 
-var ThreadWithCache = require('mail.model.ThreadWithCache');
+var SearchableThread = require('mail.model.SearchableThread');
 
 var core = require('web.core');
 var session = require('web.session');
@@ -17,9 +17,9 @@ var _t = core._t;
  * communicate from their respective 'backend' access.
  *
  * FIXME: it should inherit from mail.model.Channel, not from
- * mail.model.ThreadWithCache
+ * mail.model.SearchableThread
  */
-var SupportChannel = ThreadWithCache.extend({
+var SupportChannel = SearchableThread.extend({
 
     /**
      * @override
@@ -51,7 +51,7 @@ var SupportChannel = ThreadWithCache.extend({
         this._super.apply(this, arguments);
 
         // force stuff that should probably be in Thread (or at least
-        // ThreadWithCache), but that are currently in Channel
+        // SearchableThread), but that are currently in Channel
         this._detached = data.is_minimized;
         this._folded = data.state === 'folded';
         this._uuid = data.uuid;
@@ -100,6 +100,22 @@ var SupportChannel = ThreadWithCache.extend({
         var value = folded ? 'folded' : 'open';
         this.call('mail_service', 'updateSupportChannelState', value);
     },
+    /**
+     * FIXME: this override is necessary just because the support channel is
+     * considered as a channel, even though it does not inherit from
+     * mail.model.Channel.
+     *
+     * @returns {integer}
+     */
+    getNeedactionCounter: function () {
+        return 0;
+    },
+    /**
+     * @return {string} uuid of this channel
+     */
+    getUUID: function () {
+        return this._uuid;
+    },
     /**
      * FIXME: this method is necessary just because the support channel is
      * considered as a channel, even though it does not inherit from
@@ -128,44 +144,31 @@ var SupportChannel = ThreadWithCache.extend({
         return true;
     },
     /**
-     * Support channels are not considered as chat, so they are not displayed
-     * in the 'chat' filter of the systray messaging menu.
+     * Called when fold or detach (or both) status have changed on the support
+     * channel.
      *
-     * @override
-     * @returns {boolean}
-     */
-    isChat: function () {
-        return false;
-    },
-    /**
-     * FIXME: this override is necessary just because the support channel is
-     * considered as a channel, even though it does not inherit from
-     * mail.model.Channel.
+     * Note: this is partially a hack due to support channel not being a
+     * channel. Also, the support channel uses another way to handle its window
+     * state, by means of the local storage.
      *
-     * @returns {integer}
+     * @param {Object} params
+     * @param {boolean} [params.folded]
+     * @param {boolean} [params.detached]
      */
-    getNeedactionCounter: function () {
-        return 0;
-    },
-    /**
-     * @return {string} uuid of this channel
-     */
-    getUUID: function () {
-        return this._uuid;
-    },
-    /**
-     * Posts the message on the Support server.
-     *
-     * @override
-     * @return {$.Promise}
-     */
-    postMessage: function (data) {
-        // ensure that the poll is active before posting the message
-        this.call('mail_service', 'startPollingSupport');
-        return supportSession.rpc('/odoo_im_support/chat_post', {
-            uuid: this._supportChannelUUID,
-            message_content: data.content,
-        });
+    updateWindowState: function (params) {
+        if ('detached' in params) {
+            this._detached = params.detached;
+        }
+        if ('folded' in params) {
+            this._folded = params.folded;
+        }
+
+        if (!this._detached) {
+            this.call('mail_service', 'updateSupportChannelState', 'closed');
+        } else {
+            var value = this._folded ? 'folded' : 'open';
+            this.call('mail_service', 'updateSupportChannelState', value);
+        }
     },
 
     //--------------------------------------------------------------------------
@@ -241,6 +244,21 @@ var SupportChannel = ThreadWithCache.extend({
                 return channelCache.messages;
             });
     },
+    /**
+     * Posts the message on the Support server.
+     *
+     * @override
+     * @private
+     * @return {$.Promise}
+     */
+    _postMessage: function (data) {
+        // ensure that the poll is active before posting the message
+        this.call('mail_service', 'startPollingSupport');
+        return supportSession.rpc('/odoo_im_support/chat_post', {
+            uuid: this._supportChannelUUID,
+            message_content: data.content,
+        });
+    },
 });
 
 return SupportChannel;
diff --git a/addons/im_support/static/tests/systray_tests.js b/addons/im_support/static/tests/systray_tests.js
index 09a8f600642..3bf05417d7e 100644
--- a/addons/im_support/static/tests/systray_tests.js
+++ b/addons/im_support/static/tests/systray_tests.js
@@ -315,7 +315,7 @@ QUnit.test('receive messages in the Support channel', function (assert) {
         body: 'A message',
         channel_ids: [supportChannelID],
     };
-    var notification = [[false, 'mail.channel'], data];
+    var notification = [[false, 'mail.channel', 1], data];
     messagingMenu.call('support_bus_service', 'trigger', 'notification', [notification]);
 
     assert.strictEqual($('.o_thread_window .o_thread_message').length, 1,
diff --git a/addons/mail/static/src/js/activity.js b/addons/mail/static/src/js/activity.js
index 0a25fcfe194..8f4c6b1e7c7 100644
--- a/addons/mail/static/src/js/activity.js
+++ b/addons/mail/static/src/js/activity.js
@@ -117,7 +117,7 @@ var AbstractActivityField = AbstractField.extend({
      * @param {integer} params.activityID
      * @param {string} params.feedback
      */
-    _markActivityDone: function(params) {
+    _markActivityDone: function (params) {
         var activityID = params.activityID;
         var feedback = params.feedback;
 
@@ -134,7 +134,7 @@ var AbstractActivityField = AbstractField.extend({
      * @param {integer} params.activityID
      * @param {string} params.feedback
      */
-    _markActivityDoneAndScheduleNext: function(params) {
+    _markActivityDoneAndScheduleNext: function (params) {
         var activityID = params.activityID;
         var feedback = params.feedback;
         var self = this;
@@ -145,8 +145,7 @@ var AbstractActivityField = AbstractField.extend({
             kwargs: {feedback: feedback},
             context: this.record.getContext(),
         }).then(
-            function(rslt_action) {
-                console.log(rslt_action);
+            function (rslt_action) {
                 self.do_action(rslt_action, {
                     on_close: function () {
                         self.trigger_up('reload');
@@ -352,7 +351,7 @@ var Activity = AbstractActivityField.extend({
                 force_email: true,
             },
         };
-        return this.do_action(action, { on_close: function(){}});
+        return this.do_action(action, { on_close: function () {} });
     },
     /**
      * @private
@@ -650,7 +649,7 @@ var KanbanActivity = AbstractActivityField.extend({
                 force_email: true,
             },
         };
-        return this.do_action(action, { on_close: function(){}});
+        return this.do_action(action, { on_close: function () {} });
     },
     /**
      * @private
diff --git a/addons/mail/static/src/js/chatter.js b/addons/mail/static/src/js/chatter.js
index ca71f8a75ad..6ec365ceda4 100644
--- a/addons/mail/static/src/js/chatter.js
+++ b/addons/mail/static/src/js/chatter.js
@@ -39,9 +39,9 @@ var Chatter = Widget.extend({
      * @param {widget} parent
      * @param {Object} record
      * @param {Object} mailFields
-     * @param {boolean} [mailFields.mail_activity]
-     * @param {boolean} [mailFields.mail_followers]
-     * @param {boolean} [mailFields.mail_thread]
+     * @param {string} [mailFields.mail_activity]
+     * @param {string} [mailFields.mail_followers]
+     * @param {string} [mailFields.mail_thread]
      */
     init: function (parent, record, mailFields, options) {
         this._super.apply(this, arguments);
diff --git a/addons/mail/static/src/js/discuss.js b/addons/mail/static/src/js/discuss.js
index 80b61d983bf..2ae175666b5 100644
--- a/addons/mail/static/src/js/discuss.js
+++ b/addons/mail/static/src/js/discuss.js
@@ -195,6 +195,11 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
 
     /**
      * @override
+     * @param {Object} [options]
+    //  * @param {boolean} [options.phantomjs=false] if set, rendering of non-empty
+    //  *   thread will use 'block' display instead of 'flex', because phantomjs
+    //  *   sucks with flexbox... TODO: remove this option when we no longer use
+    //  *   phantomJS
      */
     init: function (parent, action, options) {
         this._super.apply(this, arguments);
@@ -445,15 +450,12 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
                                     !this._thread.isMassMailing(),
             displayEmptyThread: !this._thread.hasMessages() && !this.domain.length,
             displayNoMatchFound: !this._thread.hasMessages() && this.domain.length,
-            displaySubjectOnMessages:
-                (
-                    this._thread.getType() !== 'mailbox' &&
-                    this._thread.isMassMailing()
-                ) ||
+            displaySubjectOnMessages: this._thread.isMassMailing() ||
                 this._thread.getID() === 'mailbox_inbox' ||
                 this._thread.getID() === 'mailbox_moderation',
             displayEmailIcons: false,
             displayReplyIcons: true,
+            displayBottomThreadFreeSpace: true,
         };
     },
     /**
@@ -495,8 +497,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
             (this._threadWidget.el.clientHeight === this._threadWidget.el.scrollHeight) &&
             !this._thread.isAllHistoryLoaded(this.domain);
         if (loadMoreMessages) {
-            return this._loadMoreMessages()
-                        .then(this._loadEnoughMessages.bind(this));
+            return this._loadMoreMessages().then(this._loadEnoughMessages.bind(this));
         }
     },
     /**
@@ -520,8 +521,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
                     self._thread,
                     self._getThreadRenderingOptions()
                 );
-                offset += dom.getPosition(document.querySelector(oldestMessageSelector)
-                ).top;
+                offset += dom.getPosition(document.querySelector(oldestMessageSelector)).top;
                 self._threadWidget.scrollToPosition(offset);
             });
     },
@@ -558,7 +558,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
      *
      * @private
      * @param {JQuery} $input the input to prepare
-     * @param {string} type the type of thread to create ('dm', 'public' or
+     * @param {string} type the type of thread to create ('dm_chat', 'public' or
      *   'private' channel)
      */
     _prepareAddThreadInput: function ($input, type) {
@@ -569,11 +569,11 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
                     self._lastSearchVal = _.escape(request.term);
                     self._searchChannel(self._lastSearchVal).done(function (result){
                         result.push({
-                            'label':  _.str.sprintf(
+                            label:  _.str.sprintf(
                                         '<strong>' + _t("Create %s") + '</strong>',
                                         '<em>"#' + self._lastSearchVal + '"</em>'
                             ),
-                            'value': '_create',
+                            value: '_create',
                         });
                         response(result);
                     });
@@ -599,7 +599,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
                     self.call('mail_service', 'createChannel', name, 'private');
                 }
             });
-        } else if (type === 'dm') {
+        } else if (type === 'dm_chat') {
             $input.autocomplete({
                 source: function (request, response) {
                     self._lastSearchVal = _.escape(request.term);
@@ -607,11 +607,11 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
                 },
                 select: function (ev, ui) {
                     var partnerID = ui.item.id;
-                    var dm = self.call('mail_service', 'getDmFromPartnerID', partnerID);
-                    if (dm) {
-                        self._setThread(dm.getID());
+                    var dmChat = self.call('mail_service', 'getDMChatFromPartnerID', partnerID);
+                    if (dmChat) {
+                        self._setThread(dmChat.getID());
                     } else {
-                        self.call('mail_service', 'createChannel', partnerID, 'dm');
+                        self.call('mail_service', 'createChannel', partnerID, 'dm_chat');
                     }
                     // clear the input
                     $(this).val('');
@@ -693,7 +693,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
             needactionCounter: inbox.getMailboxCounter(),
             starredCounter: starred.getMailboxCounter(),
             moderationCounter: moderation ? moderation.getMailboxCounter() : 0,
-            isModerator: this.call('mail_service', 'isModerator'),
+            isMyselfModerator: this.call('mail_service', 'isMyselfModerator'),
         }));
         return $sidebar;
     },
@@ -919,7 +919,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
      */
     _unselectMessage: function () {
         this._basicComposer.do_toggle(this._thread.getType() !== 'mailbox' && !this._thread.isMassMailing());
-        this._extendedComposer.do_toggle(this._thread.getType() !== 'mailbox' && !!this._thread.isMassMailing());
+        this._extendedComposer.do_toggle(this._thread.isMassMailing());
 
         if (!config.device.isMobile) {
             var composer = this._thread.getType() !== 'mailbox' && this._thread.isMassMailing() ?
@@ -959,7 +959,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
             this._thread.getID() === 'mailbox_moderation' ||
             (
                 this._thread.isModerated() &&
-                this._thread.isModerator()
+                this._thread.isMyselfModerator()
             )
         ) {
             this._updateModerationButtons();
@@ -985,7 +985,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
      * @param {mail.model.Thread} thread
      */
     _updateControlPanelButtons: function (thread) {
-        // Hide 'unsubscribe' button in state channels and DM and channels with group-based subscription
+        // Hide 'unsubscribe' button in state channels and DM chats and channels with group-based subscription
         this.$buttons
             .find('.o_mail_discuss_button_invite, .o_mail_discuss_button_settings')
             .toggle(thread.getType() !== 'dm' && thread.getType() !== 'mailbox');
@@ -999,11 +999,11 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
             .removeClass('o_hidden');
         this.$buttons
             .find('.o_mail_discuss_button_select_all')
-            .toggle((thread.isModerated() && thread.isModerator()) || thread.getID() === 'mailbox_moderation')
+            .toggle((thread.isModerated() && thread.isMyselfModerator()) || thread.getID() === 'mailbox_moderation')
             .removeClass('o_hidden');
         this.$buttons
             .find('.o_mail_discuss_button_unselect_all')
-            .toggle((thread.isModerated() && thread.isModerator()) || thread.getID() === 'mailbox_moderation')
+            .toggle((thread.isModerated() && thread.isMyselfModerator()) || thread.getID() === 'mailbox_moderation')
             .removeClass('o_hidden');
         this.$buttons.find('.o_mail_discuss_button_moderate_all').hide();
 
@@ -1076,7 +1076,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
         });
 
         this.$('.o_mail_discuss_sidebar').html($sidebar.contents());
-        _.each(['dm', 'public', 'private'], function (type) {
+        _.each(['dm_chat', 'public', 'private'], function (type) {
             var $input = self.$('.o_mail_add_thread[data-type=' + type + '] input');
             self._prepareAddThreadInput($input, type);
         });
@@ -1153,16 +1153,16 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
     /**
      * Called when someone asks discuss whether the bottom of `thread` is
      * visible or not. An object `query` is provided in order to reponse on the
-     * key `isDisplayed`.
+     * key `isVisible`.
      *
      * @private
      * @param {mail.model.Thread} thread
      * @param {Object} query
-     * @param {boolean} query.isBottomVisible the response to provide on whether
-     *   the thread is visible in discuss.
+     * @param {boolean} query.isVisible the response to provide on whether the
+     *   bottom of the thread is visible in discuss.
      */
     _onIsThreadBottomVisible: function (thread, query) {
-        query.isBottomVisible = query.isBottomVisible ||
+        query.isVisible = query.isVisible ||
                             (
                                 thread.getID() === this._thread.getID() &&
                                 this._threadWidget.isAtBottom()
@@ -1389,7 +1389,7 @@ var Discuss = AbstractAction.extend(ControlPanelMixin, {
         ev.stopPropagation();
         var channelID = $(ev.target).data('thread-id');
         var channel = this.call('mail_service', 'getChannel', channelID);
-        if (channel.isAdministrator()) {
+        if (channel.isMyselfAdministrator()) {
             this._askConfirmationAdminUnsubscribe(channel);
         } else {
             channel.unsubscribe();
diff --git a/addons/mail/static/src/js/discuss_mobile.js b/addons/mail/static/src/js/discuss_mobile.js
index 8e3f0f86c22..fda74540688 100644
--- a/addons/mail/static/src/js/discuss_mobile.js
+++ b/addons/mail/static/src/js/discuss_mobile.js
@@ -73,7 +73,7 @@ Discuss.include({
     _renderButtons: function () {
         var self = this;
         this._super.apply(this, arguments);
-        _.each(['dm', 'public', 'private'], function (type) {
+        _.each(['dm_chat', 'public', 'private'], function (type) {
             var selector = '.o_mail_discuss_button_' + type;
             self.$buttons.on('click', selector, self._onAddThread.bind(self));
         });
@@ -106,6 +106,7 @@ Discuss.include({
      */
     _setThread: function (threadID) {
         var thread = this.call('mail_service', 'getThread', threadID);
+        this._thread = thread;
         if (thread.getType() !== 'mailbox') {
             this.call('mail_service', 'openThreadWindow', threadID);
             return $.when();
@@ -148,7 +149,7 @@ Discuss.include({
      *
      * @private
      * @param {string} type the thread's type to display (e.g. 'mailbox_inbox',
-     *   'mailbox_starred', 'dm'...).
+     *   'mailbox_starred', 'dm_chat'...).
      */
     _updateContent: function (type) {
         var self = this;
diff --git a/addons/mail/static/src/js/models/messages/abstract_message.js b/addons/mail/static/src/js/models/messages/abstract_message.js
index 420ac2da41b..f5cf55f0ef1 100644
--- a/addons/mail/static/src/js/models/messages/abstract_message.js
+++ b/addons/mail/static/src/js/models/messages/abstract_message.js
@@ -344,7 +344,7 @@ var AbstractMessage =  Class.extend({
      * @return {boolean}
      */
     shouldRedirectToAuthor: function () {
-        return !this._isAuthor();
+        return !this._isMyselfAuthor();
     },
 
     //--------------------------------------------------------------------------
@@ -370,7 +370,7 @@ var AbstractMessage =  Class.extend({
      * @private
      * @return {boolean}
      */
-    _isAuthor: function () {
+    _isMyselfAuthor: function () {
         return this.hasAuthor() && (this.getAuthorID() === session.partner_id);
     },
     /**
diff --git a/addons/mail/static/src/js/models/messages/message.js b/addons/mail/static/src/js/models/messages/message.js
index 0c6480f3264..881a5ae2c97 100644
--- a/addons/mail/static/src/js/models/messages/message.js
+++ b/addons/mail/static/src/js/models/messages/message.js
@@ -357,14 +357,6 @@ var Message =  AbstractMessage.extend(Mixins.EventDispatcherMixin, ServicesMixin
     hasTrackingValues: function () {
         return !!(this._trackingValueIDs && (this._trackingValueIDs.length > 0));
     },
-    /**
-     * State whether the current user is the author of this message
-     *
-     * @return {boolean}
-     */
-    isAuthor: function () {
-        return this._isAuthor();
-    },
     /**
      * State whether this message is linked to a document thread (not channel)
      *
@@ -381,6 +373,14 @@ var Message =  AbstractMessage.extend(Mixins.EventDispatcherMixin, ServicesMixin
     isLinkedToDocumentThread: function () {
         return !!(this._documentModel !== 'mail.channel' && this._documentID);
     },
+    /**
+     * State whether the current user is the author of this message
+     *
+     * @return {boolean}
+     */
+    isMyselfAuthor: function () {
+        return this._isMyselfAuthor();
+    },
     /**
      * States whether the current message needs moderation in general.
      *
diff --git a/addons/mail/static/src/js/models/threads/abstract_thread.js b/addons/mail/static/src/js/models/threads/abstract_thread.js
index 67929517ed4..fb6695c6a6c 100644
--- a/addons/mail/static/src/js/models/threads/abstract_thread.js
+++ b/addons/mail/static/src/js/models/threads/abstract_thread.js
@@ -2,6 +2,7 @@ odoo.define('mail.model.AbstractThread', function (require) {
 "use strict";
 
 var Class = require('web.Class');
+var Mixins = require('web.mixins');
 
 /**
  * Abstract thread is the super class of all threads, either backend threads
@@ -9,15 +10,20 @@ var Class = require('web.Class');
  *
  * Abstract threads contain abstract messages
  */
-var AbstractThread = Class.extend({
+var AbstractThread = Class.extend(Mixins.EventDispatcherMixin, {
     /**
      * @param {Object} params
      * @param {Object} params.data
      * @param {integer|string} params.data.id the ID of this thread
      * @param {string} params.data.name the name of this thread
      * @param {string} params.data.status the status of this thread
+     * @param {Object} params.parent Object with the event-dispatcher mixin
+     *   (@see {web.mixins.EventDispatcherMixin})
      */
     init: function (params) {
+        Mixins.EventDispatcherMixin.init.call(this, arguments);
+        this.setParent(params.parent);
+
         this._folded = false; // threads are unfolded by default
         this._id = params.data.id;
         this._name = params.data.name;
@@ -29,6 +35,15 @@ var AbstractThread = Class.extend({
     // Public
     //--------------------------------------------------------------------------
 
+    /**
+     * Add a message to this thread.
+     *
+     * @param {mail.model.AbstractMessage} message
+     */
+    addMessage: function (message) {
+        this._addMessage.apply(this, arguments);
+        this.trigger('message_added', message);
+    },
     /**
      * Updates the folded state of the thread
      *
@@ -87,12 +102,6 @@ var AbstractThread = Class.extend({
     hasMessages: function () {
         return !_.isEmpty(this.getMessages());
     },
-    /**
-     * Increments the unread counter of this thread by 1 unit.
-     */
-    incrementUnreadCounter: function () {
-        this._unreadCounter++;
-    },
     /**
      * States whether this thread is folded or not.
      *
@@ -101,12 +110,77 @@ var AbstractThread = Class.extend({
     isFolded: function () {
         return this._folded;
     },
+    /**
+     * Mark the thread as read, which resets the unread counter to 0. This is
+     * only performed if the unread counter is not 0.
+     *
+     * @returns {$.Promise}
+     */
+    markAsRead: function () {
+        if (this._unreadCounter > 0) {
+            return this._markAsRead();
+        }
+        return $.when();
+    },
+    /**
+     * Post a message on this thread
+     *
+     * @returns {$.Promise} resolved with the message object to be sent to the
+     *   server
+     */
+    postMessage: function () {
+        return this._postMessage.apply(this, arguments)
+                                .then(this.trigger.bind(this, 'message_posted'));
+    },
     /**
      * Resets the unread counter of this thread to 0.
      */
     resetUnreadCounter: function () {
         this._unreadCounter = 0;
     },
+
+    //--------------------------------------------------------------------------
+    // Private
+    //--------------------------------------------------------------------------
+
+    /**
+     * Add a message to this thread.
+     *
+     * @abstract
+     * @private
+     * @param {mail.model.AbstractMessage} message
+     */
+    _addMessage: function (message) {},
+    /**
+     * Increments the unread counter of this thread by 1 unit.
+     *
+     * @private
+     */
+    _incrementUnreadCounter: function () {
+        this._unreadCounter++;
+    },
+    /**
+     * Mark the thread as read
+     *
+     * @private
+     * @returns {$.Promise}
+     */
+    _markAsRead: function () {
+        this.resetUnreadCounter();
+        this._warnUpdatedUnreadCounter();
+        return $.when();
+    },
+    /**
+     * Post a message on this thread
+     *
+     * @abstract
+     * @private
+     * @returns {$.Promise} resolved with the message object to be sent to the
+     *   server
+     */
+    _postMessage: function () {
+        return $.when();
+    },
 });
 
 return AbstractThread;
diff --git a/addons/mail/static/src/js/models/threads/channel.js b/addons/mail/static/src/js/models/threads/channel.js
index a33319c7f1f..3f932ccb8ec 100644
--- a/addons/mail/static/src/js/models/threads/channel.js
+++ b/addons/mail/static/src/js/models/threads/channel.js
@@ -1,7 +1,7 @@
 odoo.define('mail.model.Channel', function (require) {
 "use strict";
 
-var ThreadWithCache = require('mail.model.ThreadWithCache');
+var SearchableThread = require('mail.model.SearchableThread');
 var mailUtils = require('mail.utils');
 
 var session = require('web.session');
@@ -15,12 +15,11 @@ var time = require('web.time');
  * Any piece of code in JS that make use of channels must ideally interact with
  * such objects, instead of direct data from the server.
  */
-var Channel = ThreadWithCache.extend({
+var Channel = SearchableThread.extend({
     /**
      * @override
      * @param {Object} params
      * @param {Object} params.data
-     * @param {string} [params.data.anonymous_name]
      * @param {string} params.data.channel_type
      * @param {integer} [params.data.create_uid] the ID of the user that has
      *   created the channel.
@@ -29,9 +28,7 @@ var Channel = ThreadWithCache.extend({
      * @param  {boolean} params.data.is_moderator whether the current user is
      *   moderator of this channel.
      * @param {string} [params.data.last_message_date] date in server-format
-     * @param {boolean} [params.data.mass_mailing]
      * @param {integer} [params.data.message_unread_counter]
-     * @param {string} [params.data.public] either 'public' or 'private'
      * @param {string} params.data.state
      * @param {string} [params.data.uuid]
      * @param {Object} params.options
@@ -48,9 +45,8 @@ var Channel = ThreadWithCache.extend({
 
         // If set, autoswitch channel on joining this channel in discuss
         // the default behaviour is to autoswitch on join.
-        // exception: receiving channel or chat session notifications
+        // exception: receiving channel session notifications
         this._autoswitch = 'autoswitch' in options ? options.autoswitch : true;
-        this._chat = undefined; // FIXME: could be dropped when livechat and DM are moved out of this class
         this._commands = undefined;
         this._creatorUID = data.create_uid;
         this._detached = data.is_minimized;
@@ -58,12 +54,12 @@ var Channel = ThreadWithCache.extend({
         this._folded = data.state === 'folded';
         // if set: hide 'Leave channel' button
         this._groupBasedSubscription = data.group_based_subscription;
-        this._isModerator = data.is_moderator;
+        this._isModerated = data.is_moderation;
+        this._isMyselfModerator = data.is_moderator;
         this._lastMessageDate = undefined;
-        this._massMailing = data.mass_mailing;
+        this._members = [];
         // Deferred that is resolved on fetched members of this channel.
         this._membersDef = undefined;
-        this._moderation = data.is_moderation;
         // number of messages that are 'needaction', which is equivalent to the
         // number of messages in this channel that are in inbox.
         this._needactionCounter = data.message_needaction_counter || 0;
@@ -78,16 +74,9 @@ var Channel = ThreadWithCache.extend({
             return !command.channel_types ||
                     _.contains(command.channel_types, self._serverType);
         });
-        if (this._type === 'channel') {
-            this._type = data.public !== 'private' ? 'public' : 'private';
-        }
-        if ('anonymous_name' in data) {
-            this._name = data.anonymous_name;
-        }
         if (data.last_message_date) {
             this._lastMessageDate = moment(time.str_to_datetime(data.last_message_date));
         }
-        this._chat = !this.getType().match(/^(public|private)$/);
         if (data.message_unread_counter) {
             this._unreadCounter = data.message_unread_counter;
         }
@@ -190,6 +179,7 @@ var Channel = ThreadWithCache.extend({
      * @returns {$.Promise<Object[]>} resolved with list of channel listeners
      */
     getMentionPartnerSuggestions: function () {
+        var self = this;
         if (!this._membersDef) {
             this._membersDef = this._rpc({
                 model: 'mail.channel',
@@ -199,6 +189,7 @@ var Channel = ThreadWithCache.extend({
                 shadow: true
             })
             .then(function (members) {
+                self._members = members;
                 return members;
             });
         }
@@ -215,7 +206,7 @@ var Channel = ThreadWithCache.extend({
      */
     getPreview: function () {
         var result = this._super.apply(this, arguments);
-        if (!this.isChat()) {
+        if (!this.isTwoUserThread()) {
             result.imageSRC = '/web/image/mail.channel/' + this.getID() + '/image_small';
         }
         var lastMessage = this.getLastMessage();
@@ -223,7 +214,7 @@ var Channel = ThreadWithCache.extend({
             author: lastMessage ? lastMessage.getDisplayedAuthor() : '',
             body: lastMessage ? mailUtils.parseAndTransform(lastMessage.getBody(), mailUtils.inline) : '',
             date: lastMessage ? lastMessage.getDate() : moment(),
-            isAuthor: this.hasMessages() && this.getLastMessage().isAuthor(),
+            isMyselfAuthor: this.hasMessages() && this.getLastMessage().isMyselfAuthor(),
         });
     },
     /**
@@ -251,15 +242,6 @@ var Channel = ThreadWithCache.extend({
     incrementNeedactionCounter: function () {
         this._needactionCounter++;
     },
-    /**
-     * Tells whether the current user is administrator of the channel.
-     * Note that there is no administrator for chat channels
-     *
-     * @returns {boolean}
-     */
-    isAdministrator: function () {
-        return session.uid === this._creatorUID && !this.isChat();
-    },
     /**
      * States whether the channel should be auto-selected on creation
      *
@@ -281,18 +263,6 @@ var Channel = ThreadWithCache.extend({
     isChannel: function () {
         return true;
     },
-    /**
-     * States whether this channel is a chat or not.
-     * These types of channels are chat:
-     * - direct messages (DM)
-     * - livechat
-     *
-     * @override
-     * @returns {boolean}
-     */
-    isChat: function () {
-        return this._chat;
-    },
     /**
      * States whether the channel auto-subscribes some users in a group
      *
@@ -308,81 +278,32 @@ var Channel = ThreadWithCache.extend({
      * @returns {boolean}
      */
     isModerated: function () {
-        return this._moderation;
+        return this._isModerated;
+    },
+    /**
+     * Tells whether the current user is administrator of the channel.
+     * Note that there is no administrator for two-user channels
+     *
+     * @returns {boolean}
+     */
+    isMyselfAdministrator: function () {
+        return session.uid === this._creatorUID && !this.isTwoUserThread();
     },
     /**
      * States whether the current user is moderator of this channel.
      *
      * @returns {boolean}
      */
-    isModerator: function () {
-        return this._isModerator;
-    },
-    /**
-     * Marks this channel as read.
-     * The last seen message will be the last message.
-     * Resolved with the last seen message, only for non-mailbox channels
-     *
-     * @override
-     * @returns {$.Promise<integer|undefined>} resolved with last message ID
-     *   seen in the channel, and when the channel has been marked as seen on
-     *   the server.
-     */
-    markAsRead: function () {
-        if (this._unreadCounter > 0) {
-            this.resetUnreadCounter();
-            return this._throttleFetchSeen();
-        }
-        return this._super.apply(this, arguments);
-    },
-    /**
-     * Prepare and send a message to the server on this channel
-     *
-     * @override
-     * @param {Object} data data related to the new message
-     * @returns {$.Promise<Object>} resolved when the message has been sent to
-     *   the server, with the object message that has been sent to the server.
-     */
-    postMessage: function (data) {
-        var self = this;
-        return this._super.apply(this, arguments).then(function (messageData) {
-            _.extend(messageData, {
-                message_type: 'comment',
-                subtype: 'mail.mt_comment',
-                command: data.command,
-            });
-            return self._rpc({
-                    model: 'mail.channel',
-                    method: data.command ? 'execute_command' : 'message_post',
-                    args: [self._id],
-                    kwargs: messageData,
-                }).then(function () {
-                    return messageData;
-                });
-        });
+    isMyselfModerator: function () {
+        return this._isMyselfModerator;
     },
     /**
      * Unsubscribes from channel
      *
+     * @abstract
      * @returns {$.Promise} resolve when unsubscribed
      */
-    unsubscribe: function () {
-        if (_.contains(['public', 'private'], this.getType())) {
-            // unfollow channel
-            return this._rpc({
-                model: 'mail.channel',
-                method: 'action_unfollow',
-                args: [[this._id]],
-            });
-        } else {
-            // unpin livechat
-            return this._rpc({
-                model: 'mail.channel',
-                method: 'channel_pin',
-                args: [this.getUUID(), false],
-            });
-        }
-    },
+    unsubscribe: function () {},
     /**
      * Updates the internal state of the channel, and reflects the changes in
      * the UI.
@@ -453,6 +374,47 @@ var Channel = ThreadWithCache.extend({
                 ['need_moderation', '=', true],
                 ['channel_ids', 'in', [this._id]]];
     },
+    /**
+     * Marks this channel as read.
+     * The last seen message will be the last message.
+     * Resolved with the last seen message, only for non-mailbox channels
+     *
+     * @override
+     * @private
+     * @returns {$.Promise} resolved when message has been marked as read
+     */
+    _markAsRead: function () {
+        var superDef = this._super.apply(this, arguments);
+        var seenDef = this._throttleFetchSeen();
+        return $.when(superDef, seenDef);
+    },
+    /**
+     * Prepare and send a message to the server on this channel.
+     *
+     * @override
+     * @private
+     * @param {Object} data data related to the new message
+     * @returns {$.Promise<Object>} resolved when the message has been sent to
+     *   the server, with the object message that has been sent to the server.
+     */
+    _postMessage: function (data) {
+        var self = this;
+        return this._super.apply(this, arguments).then(function (messageData) {
+            _.extend(messageData, {
+                message_type: 'comment',
+                subtype: 'mail.mt_comment',
+                command: data.command,
+            });
+            return self._rpc({
+                    model: 'mail.channel',
+                    method: data.command ? 'execute_command' : 'message_post',
+                    args: [self._id],
+                    kwargs: messageData,
+                }).then(function () {
+                    return messageData;
+                });
+        });
+    },
 });
 
 return Channel;
diff --git a/addons/mail/static/src/js/models/threads/dm.js b/addons/mail/static/src/js/models/threads/dm_chat.js
similarity index 66%
rename from addons/mail/static/src/js/models/threads/dm.js
rename to addons/mail/static/src/js/models/threads/dm_chat.js
index fba63830a55..767a6e32edd 100644
--- a/addons/mail/static/src/js/models/threads/dm.js
+++ b/addons/mail/static/src/js/models/threads/dm_chat.js
@@ -1,19 +1,18 @@
-odoo.define('mail.model.DM', function (require) {
+odoo.define('mail.model.DMChat', function (require) {
 "use strict";
 
-var Channel = require('mail.model.Channel');
+var TwoUserChannel = require('mail.model.TwoUserChannel');
 
 /**
- *
  * Any piece of code in JS that make use of DMs must ideally interact with
  * such objects, instead of direct data from the server.
  */
-var DM = Channel.extend({
+var DMChat = TwoUserChannel.extend({
     /**
      * @override
      * @param {Object} params
      * @param {Object} params.data
-     * @param {Object} params.data.direct_partner
+     * @param {Object[]} params.data.direct_partner
      * @param {integer} params.data.direct_partner[0].id
      * @param {string} params.data.direct_partner[0].im_status
      * @param {string} params.data.direct_partner[0].name
@@ -23,10 +22,10 @@ var DM = Channel.extend({
 
         var data = params.data;
 
-        this._type = 'dm';
-        this._name = data.direct_partner[0].name;
         this._directPartnerID = data.direct_partner[0].id;
+        this._name = data.direct_partner[0].name;
         this._status = data.direct_partner[0].im_status;
+        this._type = 'dm_chat';
     },
 
     //--------------------------------------------------------------------------
@@ -35,8 +34,8 @@ var DM = Channel.extend({
 
     /**
      * Get the direct partner ID linked to the DM, i.e. the partner ID of the
-     * user at the other end of the DM conversation. All DM do have a direct
-     * partner iD.
+     * user at the other end of the DM conversation. All DM chats do have a
+     * direct partner iD.
      *
      * @returns {integer}
      */
@@ -51,36 +50,14 @@ var DM = Channel.extend({
         result.imageSRC = '/web/image/res.partner/' + this.getDirectPartnerID() + '/image_small';
         return result;
     },
-    /**
-     * DM are chat
-     *
-     * @override
-     * @returns {boolean}
-     */
-    isChat: function () {
-        return true;
-    },
     /**
      * @param {string} newStatus
      */
     setStatus: function (newStatus) {
         this._status = newStatus;
     },
-    /**
-     * Unpin this DM
-     *
-     * @override
-     * @return {$.Promise} resolve when unpinned
-     */
-    unsubscribe: function () {
-        return this._rpc({
-            model: 'mail.channel',
-            method: 'channel_pin',
-            args: [this.getUUID(), false],
-        });
-    },
 });
 
-return DM;
+return DMChat;
 
 });
diff --git a/addons/mail/static/src/js/models/threads/document_thread.js b/addons/mail/static/src/js/models/threads/document_thread.js
index 831c46939a8..283bcf3ca66 100644
--- a/addons/mail/static/src/js/models/threads/document_thread.js
+++ b/addons/mail/static/src/js/models/threads/document_thread.js
@@ -57,28 +57,6 @@ var DocumentThread = Thread.extend({
     // Public
     //--------------------------------------------------------------------------
 
-    /**
-     * Add this message to this document thread.
-     *
-     * This is ignored if the message is already linked to this document thread.
-     *
-     * @override
-     * @param {mail.model.Message} message
-     */
-    addMessage: function (message) {
-        if (_.contains(this._messages, message)) {
-            return;
-        }
-        // update internal list of messages
-        this._messages.push(message);
-        this._messages = _.sortBy(this._messages, function (msg) {
-            return msg.getID();
-        });
-        // update message ids associated to this document thread
-        if (!_.contains(this._messageIDs, message.getID())) {
-            this._messageIDs.push(message.getID());
-        }
-    },
     /**
      * Overrides to store the thread's state in the LocalStorage, so that it is
      * shared between tabs, and restored on F5.
@@ -178,59 +156,6 @@ var DocumentThread = Thread.extend({
     isLinkedToDocument: function () {
         return true;
     },
-    /**
-     * Overrides this method so that all the messages of this document thread
-     * are marked as read on the server.
-     *
-     * @override
-     * @returns {$.Promise} resolved when messages have been marked as read on
-     *   the server.
-     */
-    markAsRead: function () {
-        this._super.apply(this, arguments);
-        return this.call('mail_service', 'markMessagesAsRead', this._messageIDs);
-    },
-    /**
-     * Post message for document thread
-     *
-     * @override
-     * @param {Object} data data related to the new message
-     * @return {$.Promise<Object>} resolved when the message has been sent to
-     *   the server, with the object message that has been sent to the server.
-     */
-    postMessage: function (data) {
-        var self = this;
-        var resModel = this.getDocumentModel();
-        var resID = this.getDocumentID();
-        return this._super.apply(this, arguments)
-            .then(function (messageData) {
-                _.extend(messageData, {
-                    context: data.context,
-                    message_type: data.message_type,
-                    subtype: data.subtype || "mail.mt_comment",
-                    subtype_id: data.subtype_id,
-                });
-                return self._rpc({
-                        model: resModel,
-                        method: 'message_post',
-                        args: [resID],
-                        kwargs: messageData,
-                    })
-                    .then(function (messageID) {
-                        return self._rpc({
-                                model: 'mail.message',
-                                method: 'message_format',
-                                args: [[messageID]],
-                            })
-                            .then(function (messages) {
-                                messages[0].model = resModel;
-                                messages[0].res_id = resID;
-                                self.call('mail_service', 'addMessage', messages[0]);
-                                return messages[0];
-                            });
-                    });
-        });
-    },
     /**
      * Set list of message IDs of this document thread
      *
@@ -259,6 +184,30 @@ var DocumentThread = Thread.extend({
     // Private
     //--------------------------------------------------------------------------
 
+    /**
+     * Add this message to this document thread.
+     *
+     * This is ignored if the message is already linked to this document thread.
+     *
+     * @override
+     * @private
+     * @param {mail.model.Message} message
+     */
+    _addMessage: function (message) {
+        this._super.apply(this, arguments);
+        if (_.contains(this._messages, message)) {
+            return;
+        }
+        // update internal list of messages
+        this._messages.push(message);
+        this._messages = _.sortBy(this._messages, function (msg) {
+            return msg.getID();
+        });
+        // update message ids associated to this document thread
+        if (!_.contains(this._messageIDs, message.getID())) {
+            this._messageIDs.push(message.getID());
+        }
+    },
     /**
      * Get most up to date messageIDs
      *
@@ -324,6 +273,63 @@ var DocumentThread = Thread.extend({
 
         });
     },
+    /**
+     * Overrides this method so that all the messages of this document thread
+     * are marked as read on the server.
+     *
+     * @override
+     * @private
+     * @returns {$.Promise} resolved when messages have been marked as read on
+     *   the server.
+     */
+    _markAsRead: function () {
+        var self = this;
+        return this._super.apply(this, arguments).then(function () {
+            self.call('mail_service', 'markMessagesAsRead', self._messageIDs);
+        });
+    },
+    /**
+     * Post message for document thread
+     *
+     * @override
+     * @private
+     * @param {Object} data data related to the new message
+     * @return {$.Promise<Object>} resolved when the message has been sent to
+     *   the server, with the object message that has been sent to the server.
+     */
+    _postMessage: function (data) {
+        var self = this;
+        var resModel = this.getDocumentModel();
+        var resID = this.getDocumentID();
+        return this._super.apply(this, arguments)
+            .then(function (messageData) {
+                _.extend(messageData, {
+                    context: data.context,
+                    message_type: data.message_type,
+                    subtype: data.subtype || "mail.mt_comment",
+                    subtype_id: data.subtype_id,
+                });
+                return self._rpc({
+                        model: resModel,
+                        method: 'message_post',
+                        args: [resID],
+                        kwargs: messageData,
+                    })
+                    .then(function (messageID) {
+                        return self._rpc({
+                                model: 'mail.message',
+                                method: 'message_format',
+                                args: [[messageID]],
+                            })
+                            .then(function (messages) {
+                                messages[0].model = resModel;
+                                messages[0].res_id = resID;
+                                self.call('mail_service', 'addMessage', messages[0]);
+                                return messages[0];
+                            });
+                    });
+        });
+    },
 });
 
 return DocumentThread;
diff --git a/addons/mail/static/src/js/models/threads/livechat.js b/addons/mail/static/src/js/models/threads/livechat.js
new file mode 100644
index 00000000000..d2aa04f926a
--- /dev/null
+++ b/addons/mail/static/src/js/models/threads/livechat.js
@@ -0,0 +1,57 @@
+odoo.define('mail.model.Livechat', function (require) {
+"use strict";
+
+var TwoUserChannel = require('mail.model.TwoUserChannel');
+
+/**
+ * backend-side of the livechat.
+ *
+ * Any piece of code in JS that make use of Livechats must ideally interact with
+ * such objects, instead of direct data from the server.
+ */
+var Livechat = TwoUserChannel.extend({
+    _WEBSITE_USER_ID: '_websiteUser',
+    _WEBSITE_USER_NAME: 'Website user',
+
+    /**
+     * @override
+     * @param {Object} params
+     * @param {Object} params.data
+     * @param {string} params.data.anonymous_name name of the website user
+     */
+    init: function (params) {
+        this._super.apply(this, arguments);
+
+        this._name = params.data.anonymous_name;
+
+        this._WEBSITE_USER_NAME = this._name;
+    },
+
+    //--------------------------------------------------------------------------
+    // Public
+    //--------------------------------------------------------------------------
+
+    /**
+     * For the livechat,
+     *
+     * @override
+     * @returns {$.Promise<Object[]>} resolved with list of livechat members
+     */
+    getMentionPartnerSuggestions: function () {
+        var self = this;
+        return this._super.apply(this, arguments).then(function () {
+            var websiteUser = _.findWhere(self._members, { id: self._WEBSITE_USER_ID });
+            if (!websiteUser) {
+                self._members.push({
+                    id: self._WEBSITE_USER_ID,
+                    name: self._WEBSITE_USER_NAME,
+                });
+            }
+            return self._members;
+        });
+    },
+});
+
+return Livechat;
+
+});
diff --git a/addons/mail/static/src/js/models/threads/mailbox.js b/addons/mail/static/src/js/models/threads/mailbox.js
index 4ba7c4e8d1f..172b5af9e3b 100644
--- a/addons/mail/static/src/js/models/threads/mailbox.js
+++ b/addons/mail/static/src/js/models/threads/mailbox.js
@@ -1,7 +1,7 @@
 odoo.define('mail.model.Mailbox', function (require) {
 "use strict";
 
-var ThreadWithCache = require('mail.model.ThreadWithCache');
+var SearchableThread = require('mail.model.SearchableThread');
 
 var core = require('web.core');
 
@@ -14,7 +14,7 @@ var _t = core._t;
  * list of messages, but the inbox does not represent a conversation: Inbox is
  * modeled as a mailbox.
  */
-var Mailbox = ThreadWithCache.extend({
+var Mailbox = SearchableThread.extend({
 
     /**
      * @override
diff --git a/addons/mail/static/src/js/models/threads/multi_user_channel.js b/addons/mail/static/src/js/models/threads/multi_user_channel.js
new file mode 100644
index 00000000000..c1681744127
--- /dev/null
+++ b/addons/mail/static/src/js/models/threads/multi_user_channel.js
@@ -0,0 +1,56 @@
+odoo.define('mail.model.MultiUserChannel', function (require) {
+"use strict";
+
+var Channel = require('mail.model.Channel');
+
+var MultiUserChannel = Channel.extend({
+    /**
+     * @override
+     * @param {Object} params
+     * @param {Object} params.data
+     * @param {boolean} [params.data.mass_mailing=false]
+     * @param {string} [params.data.public='public'] either 'public' or
+     *   'private'
+     */
+    init: function (params) {
+        this._super.apply(this, arguments);
+
+        var data = params.data;
+
+        this._isMassMailing = data.mass_mailing || false;
+        this._type = data.public !== 'private' ? 'public' : 'private';
+    },
+
+    //--------------------------------------------------------------------------
+    // Public
+    //--------------------------------------------------------------------------
+
+    /**
+     * States whether this thread has the mass mailing setting active or not.
+     * This is a server-side setting, that determine the type of composer that
+     * is used (basic or extended composer).
+     *
+     * @return {boolean}
+     */
+    isMassMailing: function () {
+        return this._isMassMailing;
+    },
+    /**
+     * Unsubscribes from channel
+     *
+     * @override
+     * @returns {$.Promise} resolve when unsubscribed
+     */
+    unsubscribe: function () {
+        return this._rpc({
+            model: 'mail.channel',
+            method: 'action_unfollow',
+            args: [[this.getID()]],
+        });
+    },
+
+});
+
+return MultiUserChannel;
+
+});
diff --git a/addons/mail/static/src/js/models/threads/thread_with_cache.js b/addons/mail/static/src/js/models/threads/searchable_thread.js
similarity index 96%
rename from addons/mail/static/src/js/models/threads/thread_with_cache.js
rename to addons/mail/static/src/js/models/threads/searchable_thread.js
index c82432c64d7..fef42c3ffc4 100644
--- a/addons/mail/static/src/js/models/threads/thread_with_cache.js
+++ b/addons/mail/static/src/js/models/threads/searchable_thread.js
@@ -1,4 +1,4 @@
-odoo.define('mail.model.ThreadWithCache', function (require) {
+odoo.define('mail.model.SearchableThread', function (require) {
 "use strict";
 
 var Thread = require('mail.model.Thread');
@@ -13,7 +13,7 @@ var session = require('web.session');
  * Any threads that are instances of this Class can be used with a search view,
  * in order to make searches on messages in a thread.
  */
-var ThreadWithCache = Thread.extend({
+var SearchableThread = Thread.extend({
 
     /**
      * @override
@@ -38,23 +38,6 @@ var ThreadWithCache = Thread.extend({
     // Public
     //--------------------------------------------------------------------------
 
-    /**
-     * Add the message to this thread
-     *
-     * @override
-     * @private
-     * @param {mail.model.Message} message
-     * @param {Array} domain
-     */
-    addMessage: function (message, domain) {
-        var cache = this._getCache(domain);
-        var index = _.sortedIndex(cache.messages, message, function (msg) {
-            return msg.getID();
-        });
-        if (cache.messages[index] !== message) {
-            cache.messages.splice(index, 0, message);
-        }
-    },
     /**
      * @override
      * @param {Array} [domain]
@@ -128,6 +111,24 @@ var ThreadWithCache = Thread.extend({
     // Private
     //--------------------------------------------------------------------------
 
+    /**
+     * Add the message to this thread
+     *
+     * @override
+     * @private
+     * @param {mail.model.Message} message
+     * @param {Array} domain
+     */
+    _addMessage: function (message, domain) {
+        this._super.apply(this, arguments);
+        var cache = this._getCache(domain);
+        var index = _.sortedIndex(cache.messages, message, function (msg) {
+            return msg.getID();
+        });
+        if (cache.messages[index] !== message) {
+            cache.messages.splice(index, 0, message);
+        }
+    },
     /**
      * Gets messages from thread
      *
@@ -202,6 +203,6 @@ var ThreadWithCache = Thread.extend({
     _getThreadDomain: function () {},
 });
 
-return ThreadWithCache;
+return SearchableThread;
 
 });
diff --git a/addons/mail/static/src/js/models/threads/thread.js b/addons/mail/static/src/js/models/threads/thread.js
index 5fcd0285a82..c9dda28dd93 100644
--- a/addons/mail/static/src/js/models/threads/thread.js
+++ b/addons/mail/static/src/js/models/threads/thread.js
@@ -5,7 +5,6 @@ var emojis = require('mail.emojis');
 var AbstractThread = require('mail.model.AbstractThread');
 var mailUtils = require('mail.utils');
 
-var Mixins = require('web.mixins');
 var ServicesMixin = require('web.ServicesMixin');
 
 /**
@@ -15,7 +14,7 @@ var ServicesMixin = require('web.ServicesMixin');
  *
  * In particular, channels and mailboxes are two different kinds of threads.
  */
-var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
+var Thread = AbstractThread.extend(ServicesMixin, {
 
     /**
      * @override
@@ -27,15 +26,9 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
      * @param {string} [params.data.type]
      */
     init: function (params) {
-        Mixins.EventDispatcherMixin.init.call(this, arguments);
-        this.setParent(params.parent);
         this._super.apply(this, arguments);
         // threads are not detached by default
         this._detached = false;
-        // if this._massMailing is set, display subject on messages, use
-        // extended composer and show "Send by messages by email" on discuss
-        // sidebar
-        this._massMailing = false;
         // on 1st request to getPreview, fetch data if incomplete. Otherwise it
         // means that there is no message in this channel.
         this._previewed = false;
@@ -48,13 +41,6 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
     // Public
     //--------------------------------------------------------------------------
 
-    /**
-     * Add a message to this thread.
-     *
-     * @abstract
-     * @param {mail.model.Message} message
-     */
-    addMessage: function (message) {},
     /**
      * Updates the _detached state of the thread. Must be overriden to reflect
      * the new state in the interface.
@@ -140,7 +126,7 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
         return {
             id: this.getID(),
             imageSRC: '/mail/static/src/img/smiley/avatar.jpg',
-            isChat: this.isChat(),
+            isTwoUserThread: this.isTwoUserThread(),
             status: this.getStatus(),
             title: this.getName(),
             unreadCounter: this.getUnreadCounter(),
@@ -188,16 +174,6 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
      * @abstract
      */
     incrementNeedactionCounter: function () {},
-    /**
-     * Increment the unread counter of this thread by 1 unit, and warn that the
-     * counter has been changed.
-     *
-     * @override
-     */
-    incrementUnreadCounter: function () {
-        this._super.apply(this, arguments);
-        this._warnUpdatedUnreadCounter();
-    },
     /**
      * States whether the thread should be auto-selected on creation
      *
@@ -222,17 +198,6 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
     isChannel: function () {
         return false;
     },
-    /**
-     * States whether this thread is a chat or not. In particular, public and
-     * private channels are not chat, but DMs and Livechats are chats. Chats
-     * are threads used for communication between two users.
-     * By default, any thread is not a chat
-     *
-     * @returns {boolean}
-     */
-    isChat: function () {
-        return false;
-    },
     /**
      * States whether this thread is detached or not.
      * A thread that is detached must have a thread window linked to itself.
@@ -256,10 +221,12 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
      * This is a server-side setting, that determine the type of composer that
      * is used (basic or extended composer).
      *
+     * By default, thread have not mass-mailings feature set.
+     *
      * @return {boolean}
      */
     isMassMailing: function () {
-        return this._massMailing;
+        return false;
     },
     /**
 
@@ -277,7 +244,18 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
      *
      * @returns {boolean}
      */
-    isModerator: function () {
+    isMyselfModerator: function () {
+        return false;
+    },
+    /**
+     * States whether this is a two-user thread or not. In particular, public
+     * and private channels are not two-user threads, but DMs and Livechats are
+     * two-user threads. Two-user threads are used for communication between
+     * two users. By default, any thread is not two-user thread.
+     *
+     * @returns {boolean}
+     */
+    isTwoUserThread: function () {
         return false;
     },
     /**
@@ -294,59 +272,6 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
     markAsPreviewed: function () {
         this._previewed = true;
     },
-    /**
-     * Mark the thread as read, which resets the unread counter to 0.
-     *
-     * @returns {$.Promise} resolved
-     */
-    markAsRead: function () {
-        if (this._unreadCounter > 0) {
-            this.resetUnreadCounter();
-        }
-        return $.when();
-    },
-    /**
-     * Post a message on the thread.
-     *
-     * This method must be completed by concrete threads,
-     * As it currently only pre-process the messages at the moment.
-     *
-     * @abstract
-     * @param {Object} data
-     * @returns {$.Promise<Object>} resolved with the message object to be sent
-     *   to the server
-     */
-    postMessage: function (data) {
-        // This message will be received from the mail composer as html content
-        // subtype but the urls will not be linkified. If the mail composer
-        // takes the responsibility to linkify the urls we end up with double
-        // linkification a bit everywhere. Ideally we want to keep the content
-        // as text internally and only make html enrichment at display time but
-        // the current design makes this quite hard to do.
-        var body = mailUtils.parseAndTransform(_.str.trim(data.content), mailUtils.addLink);
-        body = this._generateEmojis(body);
-        var messageData = {
-            partner_ids: data.partner_ids,
-            body: body,
-            attachment_ids: data.attachment_ids,
-            canned_response_ids: data.canned_response_ids,
-        };
-        if ('subject' in data) {
-            messageData.subject = data.subject;
-        }
-        return $.when(messageData);
-    },
-    /**
-     * Overrides the method so that it also warns that the counter has been
-     * changed on this thread.
-     *
-     * @override
-     * @private
-     */
-    resetUnreadCounter: function () {
-        this._super.apply(this, arguments);
-        this._warnUpdatedUnreadCounter();
-    },
 
     //--------------------------------------------------------------------------
     // Private
@@ -379,13 +304,58 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
         return htmlString;
     },
     /**
-     * Warn on the chat bus that the unread counter has been updated
+     * Increment the unread counter of this thread by 1 unit, and warn that the
+     * counter has been changed.
      *
+     * @override
+     * @private
+     */
+    _incrementUnreadCounter: function () {
+        this._super.apply(this, arguments);
+        this._warnUpdatedUnreadCounter();
+    },
+    /**
+     * Post a message on the thread.
+     *
+     * This method must be completed by concrete threads,
+     * As it currently only pre-process the messages at the moment.
+     *
+     * @abstract
+     * @private
+     * @param {Object} data
+     * @returns {$.Promise<Object>} resolved with the message object to be sent
+     *   to the server
+     */
+    _postMessage: function (data) {
+        // This message will be received from the mail composer as html content
+        // subtype but the urls will not be linkified. If the mail composer
+        // takes the responsibility to linkify the urls we end up with double
+        // linkification a bit everywhere. Ideally we want to keep the content
+        // as text internally and only make html enrichment at display time but
+        // the current design makes this quite hard to do.
+        var body = mailUtils.parseAndTransform(_.str.trim(data.content), mailUtils.addLink);
+        body = this._generateEmojis(body);
+        var messageData = {
+            partner_ids: data.partner_ids,
+            body: body,
+            attachment_ids: data.attachment_ids,
+            canned_response_ids: data.canned_response_ids,
+        };
+        if ('subject' in data) {
+            messageData.subject = data.subject;
+        }
+        return this._super.apply(this, arguments).then(function () {
+            return $.when(messageData);
+        });
+    },
+    /**
+     * Warn on the mail bus that the unread counter has been updated
+     *
+     * @override
      * @private
      */
     _warnUpdatedUnreadCounter: function () {
-        this.call('mail_service', 'getMailBus')
-            .trigger('update_thread_unread_counter', this);
+        this.call('mail_service', 'getMailBus').trigger('update_thread_unread_counter', this);
     },
     /**
      * Warn other mail components that the window state of this thread has
@@ -393,6 +363,7 @@ var Thread = AbstractThread.extend(Mixins.EventDispatcherMixin, ServicesMixin, {
      *
      * @private
      * @param {Object} [options={}]
+     * @param {boolean} [options.passively=false]
      */
     _warnUpdatedWindowState: function (options) {
         options = options || {};
diff --git a/addons/mail/static/src/js/models/threads/two_user_channel.js b/addons/mail/static/src/js/models/threads/two_user_channel.js
new file mode 100644
index 00000000000..204fd95eb82
--- /dev/null
+++ b/addons/mail/static/src/js/models/threads/two_user_channel.js
@@ -0,0 +1,32 @@
+odoo.define('mail.model.TwoUserChannel', function (require) {
+"use strict";
+
+var Channel = require('mail.model.Channel');
+
+var TwoUserChannel = Channel.extend({
+    /**
+     * @override
+     * @returns {boolean}
+     */
+    isTwoUserThread: function () {
+        return true;
+    },
+    /**
+     * Unpin from two-user thread
+     *
+     * @override
+     * @returns {$.Promise} resolve when unsubscribed
+     */
+    unsubscribe: function () {
+        return this._rpc({
+            model: 'mail.channel',
+            method: 'channel_pin',
+            args: [this.getUUID(), false],
+        });
+    },
+
+});
+
+return TwoUserChannel;
+
+});
diff --git a/addons/mail/static/src/js/services/mail_manager.js b/addons/mail/static/src/js/services/mail_manager.js
index 23d19caf31f..35659d04c7b 100644
--- a/addons/mail/static/src/js/services/mail_manager.js
+++ b/addons/mail/static/src/js/services/mail_manager.js
@@ -26,11 +26,12 @@ odoo.define('mail.Manager', function (require) {
  */
 var AbstractService = require('web.AbstractService');
 
-var Channel = require('mail.model.Channel');
-var DM = require('mail.model.DM');
+var DMChat = require('mail.model.DMChat');
+var Livechat = require('mail.model.Livechat');
 var Mailbox = require('mail.model.Mailbox');
 var MailFailure = require('mail.model.MailFailure');
 var Message = require('mail.model.Message');
+var MultiUserChannel = require('mail.model.MultiUserChannel');
 var mailUtils = require('mail.utils');
 
 var Bus = require('web.Bus');
@@ -39,7 +40,6 @@ var core = require('web.core');
 var session = require('web.session');
 
 var _t = core._t;
-var _lt = core._lt;
 
 var PREVIEW_MSG_MAX_SIZE = 350;  // optimal for native english speakers
 
@@ -52,30 +52,10 @@ var MailManager =  AbstractService.extend({
      * @override
      */
     start: function () {
-        this._cannedResponses = [];
-        this._mailBus = new Bus(this);
-        this._commands = [];
-        this._discussMenuID = undefined;
-        this._discussOpen = false;
-        this._isModerator = false;
-        this._mailFailures = [];
-        // list of employees for chatter mentions
-        this._mentionPartnerSuggestions = [];
-        this._messages = [];
-        this._moderatedChannelIDs = [];
-        // # of message received when odoo is out of focus
-        this._outOfFocusUnreadMessageCounter = 0;
-        // partner_ids we have a pinned DM with
-        this._pinnedDmPartners = [];
-        // all threads, including channels, DM, mailboxes, document threads, ...
-        this._threads = [];
-
-        // listen on buses
-        this._mailBus
-            .on('discuss_open', this, this._onDiscussOpen)
-            .on('window_focus', this, this._onWindowFocus);
-
-        this._initializeFromServer();
+        this._super.apply(this, arguments);
+        this._initializeInternalState();
+        this._listenOnBuses();
+        this._fetchMailStateFromServer();
     },
 
     //--------------------------------------------------------------------------
@@ -100,17 +80,7 @@ var MailManager =  AbstractService.extend({
         options = options || {};
         var message = this.getMessage(data.id);
         if (!message) {
-            message = this._makeMessage(data);
-            // Keep the array ordered by ID when inserting the new message
-            var index = _.sortedIndex(this._messages, message, function (msg) {
-                return msg.getID();
-            });
-            this._messages.splice(index, 0, message);
-            this._addNewMessagePostprocessThread(message, options);
-            this._addMessageToThreads(message, []);
-            if (!options.silent) {
-                this._mailBus.trigger('new_message', message);
-            }
+            message = this._addNewMessage(data, options);
         } else {
             if (data.moderation_status === 'accepted') {
                 message.setModerationStatus('accepted', {
@@ -124,16 +94,17 @@ var MailManager =  AbstractService.extend({
         return message;
     },
     /**
-     * Creates a channel, can be either a true channel or a DM based on `type`
+     * Creates a channel, can be either a true channel or a DM chat based on
+     * `type`
      *
      * @param {integer|string} name id of partner (in case of dm) or name
-     * @param {string} type ['dm', 'public', 'private']
+     * @param {string} type ['dm_chat', 'public', 'private']
      * @returns {$.Promise<integer>} resolved with ID of the newly created
      *   channel
      */
     createChannel: function (name, type) {
-        if (type === 'dm') {
-            return this._createDM(name);
+        if (type === 'dm_chat') {
+            return this._createDMChat(name);
         } else {
             return this._createChannel(name, type);
         }
@@ -202,9 +173,9 @@ var MailManager =  AbstractService.extend({
      * @param {integer} partnerID
      * @returns {Object|undefined} channel
      */
-    getDmFromPartnerID: function (partnerID) {
+    getDMChatFromPartnerID: function (partnerID) {
         return _.find(this._threads, function (thread) {
-            return thread.getType() === 'dm' &&
+            return thread.getType() === 'dm_chat' &&
                     thread.getDirectPartnerID() === partnerID;
         });
     },
@@ -314,8 +285,8 @@ var MailManager =  AbstractService.extend({
      *
      * @returns {boolean}
      */
-    isModerator: function () {
-        return this._isModerator;
+    isMyselfModerator: function () {
+        return this._isMyselfModerator;
     },
     /**
      * States whether the mail manager is ready or not
@@ -381,7 +352,7 @@ var MailManager =  AbstractService.extend({
      * Special redirection handling for given model and id
      *
      * If the model is res.partner, and there is a user associated with this
-     * partner which isn't the current user, open the DM with this user.
+     * partner which isn't the current user, open the DM chat with this user.
      * Otherwhise, open the record's form view (if not current user's).
      *
      * @param {string} resModel model to open
@@ -530,6 +501,28 @@ var MailManager =  AbstractService.extend({
             }
         });
     },
+    /**
+     * Add a new message
+     *
+     * @private
+     * @param {Object} data
+     * @param {Object} options
+     * @returns {mail.model.Message}
+     */
+    _addNewMessage: function (data, options) {
+        var message = this._makeMessage(data);
+        // Keep the array ordered by ID when inserting the new message
+        var index = _.sortedIndex(this._messages, message, function (msg) {
+            return msg.getID();
+        });
+        this._messages.splice(index, 0, message);
+        this._addNewMessagePostprocessThread(message, options);
+        this._addMessageToThreads(message, []);
+        if (!options.silent) {
+            this._mailBus.trigger('new_message', message);
+        }
+        return message;
+    },
     /**
      * For newly added message, postprocess threads linked to this message
      *
@@ -547,13 +540,14 @@ var MailManager =  AbstractService.extend({
             if (thread) {
                 if (
                     thread.getType() !== 'mailbox' &&
-                    !message.isAuthor() &&
+                    !message.isMyselfAuthor() &&
                     !message.isSystemNotification()
                 ) {
+                    // HERE (remove below line for final version)
                     if (options.incrementUnread) {
                         thread.incrementUnreadCounter();
                     }
-                    if (thread.isChat() && options.showNotification) {
+                    if (thread.isTwoUserThread() && options.showNotification) {
                         if (
                             !self._isDiscussOpen() &&
                             !config.device.isMobile &&
@@ -563,10 +557,10 @@ var MailManager =  AbstractService.extend({
                             // while keeping it unread
                             thread.detach({ passively: true });
                         }
-                        var query = { isBottomVisible: false };
+                        var query = { isVisible: false };
                         self._mailBus.trigger('is_thread_bottom_visible', thread, query);
-                        if (!query.isBottomVisible) {
-                            self._notifyIncomingMessage(message, query);
+                        if (!self.call('bus_service', 'isOdooFocused') || !query.isVisible) {
+                            self._notifyIncomingMessage(message);
                         }
                     }
                 }
@@ -598,7 +592,7 @@ var MailManager =  AbstractService.extend({
      * @param {string} name
      * @returns {$.Promise<integer>} ID of the created channel
      */
-    _createDM: function (name) {
+    _createDMChat: function (name) {
         var context = _.extend({ isMobile: config.device.isMobile }, session.user_context);
         return this._rpc({
                 model: 'mail.channel',
@@ -620,6 +614,25 @@ var MailManager =  AbstractService.extend({
                 args: [channelIDs],
             }, { shadow: true });
     },
+    /**
+     * @private
+     */
+    _fetchMailStateFromServer: function () {
+        var self = this;
+        this._isReady = session.is_bound.then(function () {
+            var context = _.extend(
+                { isMobile: config.device.isMobile },
+                session.user_context
+            );
+            return self._rpc({
+                route: '/mail/init_messaging',
+                params: { context: context },
+            });
+        }).then(function (result) {
+            self._updateInternalStateFromServer(result);
+            self.call('bus_service', 'startPolling');
+        });
+    },
     /**
      * Get previews of the channels
      *
@@ -744,9 +757,9 @@ var MailManager =  AbstractService.extend({
                 return false;
             }
             if (filter === 'chat') {
-                return thread.isChat();
+                return thread.isTwoUserThread();
             } else if (filter === 'channels') {
-                return !thread.isChat();
+                return !thread.isTwoUserThread();
             }
             return true;
         });
@@ -809,6 +822,8 @@ var MailManager =  AbstractService.extend({
      *
      * @private
      * @param {string|undefined} [filter]
+     * @returns {$.Promise<Object[]>} resolved with list of object that are
+     *     compatible with preview template of mail systray menu
      */
     _getSystrayStaticPreviews: function (filter) {
         var elems = [];
@@ -827,132 +842,29 @@ var MailManager =  AbstractService.extend({
         return $.when(elems);
     },
     /**
-     * Initialize the canned responses from the server data
+     * Initialize the internal state of the mail service. Ensure that all
+     * attributes are set before doing any operation on them.
      *
      * @private
-     * @param {Object} data
-     * @param {Object[]} [data.shortcodes]
-     * @param {integer} data.shortcodes[i].id
-     * @param {string} data.shortcodes[i].source
-     * @param {string} data.shortcodes[i].substitution
      */
-    _initializeCannedResponses: function (data) {
-        var self = this;
-        _.each(data.shortcodes, function (s) {
-            var cannedResponse = _.pick(s, ['id', 'source', 'substitution']);
-            self._cannedResponses.push(cannedResponse);
-        });
-    },
-    /**
-     * Initialize the channels from the server, including public, private, DM,
-     * livechat, etc.
-     *
-     * @private
-     * @param {Object} data
-     * @param {Object} [data.channel_slots] contains the data of channels to
-     *   initialize, which are grouped by channel type by key of the object
-     *   (e.g. list of public channel data are stored in 'channel_channel')
-     * @param {Object[]} [data.channel_slots[i] list of data of channel of type
-     *   `i`
-     */
-    _initializeChannels: function (data) {
-        var self = this;
-        _.each(data.channel_slots, function (channels) {
-            _.each(channels, self._addChannel.bind(self));
-        });
-    },
-    /**
-     * Initialize commands from the server
-     *
-     * @private
-     * @param {Object} data
-     * @param {Object[]} data.commands list of command data from the server
-     */
-    _initializeCommands: function (data) {
-        this._commands = _.map(data.commands, function (command) {
-            return _.extend({ id: command.name }, command);
-        });
-    },
-    /**
-     * @private
-     * @returns {$.Promise}
-     */
-    _initializeFromServer: function () {
-        var self = this;
-        this._isReady = session.is_bound.then(function () {
-            var context = _.extend(
-                { isMobile: config.device.isMobile },
-                session.user_context
-            );
-            return self._rpc({
-                route: '/mail/init_messaging',
-                params: { context: context },
-            });
-        }).then(function (result) {
-            self._updateFromServer(result);
-            self.call('bus_service', 'startPolling');
-        });
-    },
-    /**
-     * Initialize the mailboxes, namely 'Inbox', 'Starred',
-     * and 'Moderation Queue' if the user is a moderator of a channel
-     *
-     * @private
-     * @param {Object} data
-     * @param {boolean} [data.is_moderator=false] states whether the user is
-     *   moderator of a channel
-     * @param {integer} [data.moderation_counter=0] states the mailbox counter
-     *   to set to 'Moderation Queue'
-     * @param {integer} [data.needaction_inbox_counter=0] states the mailbox
-     *   counter to set to 'Inbox'
-     * @param {integer} [data.starred_counter=0] states the mailbox counter to
-     *   set to 'Starred'
-     */
-    _initializeMailboxes: function (data) {
-        this._addMailbox({
-            id: 'inbox',
-            name: _t("Inbox"),
-            mailboxCounter: data.needaction_inbox_counter || 0,
-        });
-        this._addMailbox({
-            id: 'starred',
-            name: _t("Starred"),
-            mailboxCounter: data.starred_counter || 0,
-        });
-
-        if (data.is_moderator) {
-            this._addMailbox({
-                id: 'moderation',
-                name: _t("Moderate Messages"),
-                mailboxCounter: data.moderation_counter || 0,
-            });
-        }
-    },
-    /**
-     * Initialize mail failures from the server data
-     *
-     * @private
-     * @param {Object} data
-     * @param {Object[]} data.mail_failures data to initialize mail failures
-     *   locally
-     */
-    _initializeMailFailures: function (data) {
-        var self = this;
-        this._mailFailures = _.map(data.mail_failures, function (mailFailureData) {
-            return new MailFailure(self, mailFailureData);
-        });
-    },
-    /**
-     * Initialize moderation settings from the server data
-     *
-     * @private
-     * @param {Object} data
-     * @param {boolean} [data.is_moderator=false]
-     * @param {integer[]} [data.moderation_channel_ids]
-     */
-    _initializeModerationSettings: function (data) {
-        this._moderatedChannelIDs = data.moderation_channel_ids;
-        this._isModerator = data.is_moderator;
+    _initializeInternalState: function () {
+        this._cannedResponses = [];
+        this._mailBus = new Bus(this);
+        this._commands = [];
+        this._discussMenuID = undefined;
+        this._discussOpen = false;
+        this._isMyselfModerator = false;
+        this._mailFailures = [];
+        // list of employees for chatter mentions
+        this._mentionPartnerSuggestions = [];
+        this._messages = [];
+        this._moderatedChannelIDs = [];
+        // # of message received when odoo is out of focus
+        this._outOfFocusUnreadMessageCounter = 0;
+        // partner_ids we have a pinned DM chat with
+        this._pinnedDmPartners = [];
+        // all threads, including channels, DM, mailboxes, document threads, ...
+        this._threads = [];
     },
     /**
      * State whether discuss app is open or not
@@ -982,26 +894,46 @@ var MailManager =  AbstractService.extend({
                 return self._addChannel(result, options);
             });
     },
+    /**
+     * Listen on several buses, before doing any action that trigger something
+     * on those buses.
+     *
+     * @private
+     */
+    _listenOnBuses: function () {
+        this._mailBus.on('discuss_open', this, this._onDiscussOpen);
+        this.call('bus_service', 'on', 'window_focus', this, this._onWindowFocus);
+    },
     /**
      * Creates a new instance of Channel with the given data and options.
      *
      * @private
      * @param {Object} data
+     * @param {Array} [data.channel_type] if set and is 'livechat', the channel
+     *   is a Livechat.
      * @param {Array} [data.direct_partner] if set and is an non-empty array,
-     *   the channel is a DM
+     *   the channel is a DM chat
      * @param {Object} [options]
      * @returns {mail.model.Channel}
      */
     _makeChannel: function (data, options) {
         if (_.size(data.direct_partner) > 0) {
-            return new DM({
+            return new DMChat({
                 parent: this,
                 data: data,
                 options: options,
                 commands: this._commands
             });
         }
-        return new Channel({
+        if (data.channel_type === 'livechat') {
+            return new Livechat({
+                parent: this,
+                data: data,
+                options: options,
+                commands: this._commands,
+            });
+        }
+        return new MultiUserChannel({
             parent: this,
             data: data,
             options: options,
@@ -1020,16 +952,13 @@ var MailManager =  AbstractService.extend({
     },
     /**
      * shows a popup to notify a new received message.
-     * This will also rename the odoo tab browser if
-     * the user has no focus on it.
+     * This will also rename the browser tab if this is not the active tab.
      *
      * @private
      * @param {mail.model.Message} message message received
-     * @param {Object} options
-     * @param {boolean} options.isDisplayed
      */
-    _notifyIncomingMessage: function (message, options) {
-        if (this.call('bus_service', 'isOdooFocused') && options.isDisplayed) {
+    _notifyIncomingMessage: function (message) {
+        if (this.call('bus_service', 'isOdooFocused')) {
             // no need to notify
             return;
         }
@@ -1209,7 +1138,7 @@ var MailManager =  AbstractService.extend({
      * Sort previews
      *
      *      1. unread,
-     *      2. chat,
+     *      2. two-user thread,
      *      3. date,
      *
      * @private
@@ -1219,13 +1148,13 @@ var MailManager =  AbstractService.extend({
     _sortPreviews: function (previews) {
         var res = previews.sort(function (p1, p2) {
             var unreadDiff = Math.min(1, p2.unreadCounter) - Math.min(1, p1.unreadCounter);
-            var isChatDiff = p2.isChat - p1.isChat;
+            var isTwoUserThreadDiff = p2.isTwoUserThread - p1.isTwoUserThread;
             var dateDiff = (!!p2.date - !!p1.date) ||
                               (
                                 p2.date &&
                                 p2.date.diff(p1.date)
                               );
-            return  unreadDiff || isChatDiff || dateDiff;
+            return  unreadDiff || isTwoUserThreadDiff || dateDiff;
         });
         return res;
     },
@@ -1244,6 +1173,53 @@ var MailManager =  AbstractService.extend({
             return _.isString(name) ? name.toLowerCase() : '';
         });
     },
+    /**
+     * Update the canned responses with mail data fetched from the server
+     *
+     * @private
+     * @param {Object} data
+     * @param {Object[]} [data.shortcodes]
+     * @param {integer} data.shortcodes[i].id
+     * @param {string} data.shortcodes[i].source
+     * @param {string} data.shortcodes[i].substitution
+     */
+    _updateCannedResponsesFromServer: function (data) {
+        var self = this;
+        _.each(data.shortcodes, function (s) {
+            var cannedResponse = _.pick(s, ['id', 'source', 'substitution']);
+            self._cannedResponses.push(cannedResponse);
+        });
+    },
+    /**
+     * Update the channels with the mail data fetched from server, including
+     * public, private, DM, livechat, etc.
+     *
+     * @private
+     * @param {Object} data
+     * @param {Object} [data.channel_slots] contains the data of channels to
+     *   update, which are grouped by channel type by key of the object
+     *   (e.g. list of public channel data are stored in 'channel_channel')
+     * @param {Object[]} [data.channel_slots[i] list of data of channel of type
+     *   `i`
+     */
+    _updateChannelsFromServer: function (data) {
+        var self = this;
+        _.each(data.channel_slots, function (channels) {
+            _.each(channels, self._addChannel.bind(self));
+        });
+    },
+    /**
+     * Update commands from mail data fetched from the server
+     *
+     * @private
+     * @param {Object} data
+     * @param {Object[]} data.commands list of command data from the server
+     */
+    _updateCommandsFromServer: function (data) {
+        this._commands = _.map(data.commands, function (command) {
+            return _.extend({ id: command.name }, command);
+        });
+    },
     /**
      * Update internal state from server data (mail/init_messaging rpc result)
      *
@@ -1253,18 +1229,79 @@ var MailManager =  AbstractService.extend({
      *   with all the employees
      * @param {integer} result.menu_id the menu ID of discuss app
      */
-    _updateFromServer: function (result) {
+    _updateInternalStateFromServer: function (result) {
         // commands are needed for channel instantiation
-        this._initializeCommands(result);
-        this._initializeChannels(result);
-        this._initializeModerationSettings(result);
-        this._initializeMailboxes(result);
-        this._initializeMailFailures(result);
-        this._initializeCannedResponses(result);
+        this._updateCommandsFromServer(result);
+        this._updateChannelsFromServer(result);
+        this._updateModerationSettingsFromServer(result);
+        this._updateMailboxesFromServer(result);
+        this._updateMailFailuresFromServer(result);
+        this._updateCannedResponsesFromServer(result);
 
         this._mentionPartnerSuggestions = result.mention_partner_suggestions;
         this._discussMenuID = result.menu_id;
     },
+    /**
+     * Update the mailboxes with mail data fetched from server, namely 'Inbox',
+     * 'Starred', and 'Moderation Queue' if the user is a moderator of a channel
+     *
+     * @private
+     * @param {Object} data
+     * @param {boolean} [data.is_moderator=false] states whether the user is
+     *   moderator of a channel
+     * @param {integer} [data.moderation_counter=0] states the mailbox counter
+     *   to set to 'Moderation Queue'
+     * @param {integer} [data.needaction_inbox_counter=0] states the mailbox
+     *   counter to set to 'Inbox'
+     * @param {integer} [data.starred_counter=0] states the mailbox counter to
+     *   set to 'Starred'
+     */
+    _updateMailboxesFromServer: function (data) {
+        this._addMailbox({
+            id: 'inbox',
+            name: _t("Inbox"),
+            mailboxCounter: data.needaction_inbox_counter || 0,
+        });
+        this._addMailbox({
+            id: 'starred',
+            name: _t("Starred"),
+            mailboxCounter: data.starred_counter || 0,
+        });
+
+        if (data.is_moderator) {
+            this._addMailbox({
+                id: 'moderation',
+                name: _t("Moderate Messages"),
+                mailboxCounter: data.moderation_counter || 0,
+            });
+        }
+    },
+    /**
+     * Update mail failures with mail data fetched from the server
+     *
+     * @private
+     * @param {Object} data
+     * @param {Object[]} data.mail_failures data to update mail failures
+     *   locally
+     */
+    _updateMailFailuresFromServer: function (data) {
+        var self = this;
+        this._mailFailures = _.map(data.mail_failures, function (mailFailureData) {
+            return new MailFailure(self, mailFailureData);
+        });
+    },
+    /**
+     * Update moderation settings with mail data fetched from server
+     *
+     * @private
+     * @param {Object} data
+     * @param {boolean} [data.is_moderator=false]
+     * @param {integer[]} [data.moderation_channel_ids]
+     */
+    _updateModerationSettingsFromServer: function (data) {
+        this._isMyselfModerator = data.is_moderator;
+        this._moderatedChannelIDs = data.moderation_channel_ids;
+    },
 
     //--------------------------------------------------------------------------
     // Handlers
diff --git a/addons/mail/static/src/js/services/mail_notification_manager.js b/addons/mail/static/src/js/services/mail_notification_manager.js
index 475cbd44f90..0e1fc4782d3 100644
--- a/addons/mail/static/src/js/services/mail_notification_manager.js
+++ b/addons/mail/static/src/js/services/mail_notification_manager.js
@@ -11,16 +11,12 @@ var MailManager = require('mail.Manager');
 var MailFailure = require('mail.model.MailFailure');
 
 var core = require('web.core');
+var session = require('web.session');
 
 var _t = core._t;
 
 MailManager.include({
 
-    start: function () {
-        this._super.apply(this, arguments);
-        this.call('bus_service', 'onNotification', this, this._onNotification);
-    },
-
     //--------------------------------------------------------------------------
     // Private
     //--------------------------------------------------------------------------
@@ -51,8 +47,9 @@ MailManager.include({
      *
      * @private
      * @param {Object} messageData
-     * @param {Array} messageData.channel_ids list of integers and strings,
-     *      where strings for static channels, e.g. 'mailbox_inbox'.
+     * @param {integer[]} messageData.channel_ids channel IDs of this message
+     *   (note that 'pending moderation' messages in moderated channels do not
+     *   have the moderated channels in this array).
      */
     _handleChannelNotification: function (messageData) {
         var self = this;
@@ -415,29 +412,36 @@ MailManager.include({
      * @param {Array} data.messages message to display on notification
      */
     _handlePartnerUserConnectionNotification: function (data) {
-        var self=this;
-        var partner_id = data.partner_id;
-        this.call('bus_service', 'sendNotification', data.title, data.message, function(){
-            self.call('mail_service', 'openDmWindow', partner_id);
+        var self = this;
+        var partnerID = data.partner_id;
+        this.call('bus_service', 'sendNotification', data.title, data.message, function ( ){
+            self.call('mail_service', 'openDmWindow', partnerID);
         });
     },
     /**
-     * 
      * On receiving an update on user status (e.g. becoming 'online', 'offline',
      * 'idle', etc.).
      *
      * @private
      * @param {Object} data partner infos
-     * @param {integer} data.id
-     * @param {string} data.im_status
+     * @param {integer} data.id partner ID
+     * @param {string} data.im_status partner new 'im status' (e.g. 'online')
      */
     _handlePresenceNotification: function (data) {
-        var dm = this.getDmFromPartnerID(data.id);
-        if (dm) {
-            dm.setStatus(data.im_status);
-            this._mailBus.trigger('update_dm_presence', dm);
+        var dmChat = this.getDMChatFromPartnerID(data.id);
+        if (dmChat) {
+            dmChat.setStatus(data.im_status);
+            this._mailBus.trigger('update_dm_presence', dmChat);
         }
     },
+    /**
+     * @override
+     * @private
+     */
+    _listenOnBuses: function () {
+        this._super.apply(this, arguments);
+        this.call('bus_service', 'onNotification', this, this._onNotification);
+    },
     /**
      * Update the message notification status of message based on update_message
      *
@@ -481,17 +485,12 @@ MailManager.include({
         _.each(notifs, function (notif) {
             var model = notif[0][1];
             if (model === 'ir.needaction') {
-                // new message in the inbox
                 self._handleNeedactionNotification(notif[1]);
             } else if (model === 'mail.channel') {
-                // new message in a channel
                 self._handleChannelNotification(notif[1]);
             } else if (model === 'res.partner') {
-                // channel joined/left, message marked as read/(un)starred,
-                // chat open/closed, moderation specific, etc.
                 self._handlePartnerNotification(notif[1]);
             } else if (model === 'bus.presence') {
-                // update presence of users
                 self._handlePresenceNotification(notif[1]);
             }
         });
diff --git a/addons/mail/static/src/js/services/mail_window_manager.js b/addons/mail/static/src/js/services/mail_window_manager.js
index 733ca366a95..6b15a5a9a38 100644
--- a/addons/mail/static/src/js/services/mail_window_manager.js
+++ b/addons/mail/static/src/js/services/mail_window_manager.js
@@ -20,35 +20,13 @@ var THREAD_WINDOW_WIDTH = 325 + 5;  // 5 pixels between windows
  * windows.
  */
 MailManager.include({
+    custom_events: _.extend({}, MailManager.prototype.custom_events, {
+        close_blank_thread_window: '_onCloseBlankThreadWindow',
+    }),
 
     // tell where to append thread window
     THREAD_WINDOW_APPENDTO: 'body',
 
-    start: function () {
-        this._super.apply(this, arguments);
-
-        this._availableSlotsForThreadWindows = 0;
-        this._hiddenThreadWindows = [];
-        // used to keep dropdown open when closing thread windows
-        this._keepHiddenThreadWindowsDropdownOpen = false;
-        this._spaceLeftForThreadWindows = 0;
-        this._threadWindows = [];
-        // jQuery element for the dropdown of hidden thread windows
-        // see _renderHiddenThreadWindowsDropdown
-        this._$hiddenThreadWindowsDropdown = null;
-
-        this._mailBus
-            .on('update_message', this, this._onUpdateMessage)
-            .on('new_message', this, this._onNewMessage)
-            .on('new_channel', this, this._onNewChannel)
-            .on('is_thread_bottom_visible', this, this._onIsThreadBottomVisible)
-            .on('unsubscribe_from_channel', this, this._onUnsubscribeFromChannel)
-            .on('update_thread_unread_counter', this, this._onUpdateThreadUnreadCounter)
-            .on('update_dm_presence', this, this._onUpdateDmPresence);
-
-        core.bus.on('resize', this, _.debounce(this._repositionThreadWindows.bind(this), 100));
-    },
-
     //--------------------------------------------------------------------------
     // Public
     //--------------------------------------------------------------------------
@@ -73,18 +51,20 @@ MailManager.include({
         }
     },
     /**
-     * Open a DM in a thread window. This is useful when selecting a DM in the
-     * blank thread window, so that it replaces it with the DM window.
+     * Open a DM chat in a thread window. This is useful when selecting a DM
+     * chatin the blank thread window, so that it replaces it with the DM chat
+     * window.
      *
      * @param {integer} partnerID
      */
-    openDmWindow: function (partnerID) {
-        var dm = this.getDmFromPartnerID(partnerID);
-        if (!dm) {
-            this._openAndDetachDm(partnerID);
+    openDMChatWindowFromBlankThreadWindow: function (partnerID) {
+        var dmChat = this.getDMChatFromPartnerID(partnerID);
+        if (!dmChat) {
+            this._openAndDetachDMChat(partnerID);
         } else {
-            this.openThreadWindow(dm.getID());
+            this.openThreadWindow(dmChat.getID());
         }
+        this._closeBlankThreadWindow();
     },
     /**
      * Open the thread window if discuss is not opened
@@ -129,29 +109,11 @@ MailManager.include({
                     return thread.fetchMessages();
                 }).then(function () {
                     threadWindow.render();
-                    threadWindow.threadWidget.scrollToBottom();
-                    // setTimeout to prevent to execute handler on first
-                    // scrollTo, which is asynchronous
-                    setTimeout(function () {
-                        threadWindow.threadWidget.$el.on('scroll', null, _.debounce(function () {
-                            if (
-                                !threadWindow.isPassive() &&
-                                threadWindow.threadWidget.isAtBottom()
-                            ) {
-                                thread.markAsRead();
-                            }
-                        }, 100));
-                    }, 0);
-                    if (options.passively) {
-                        // mark first unread messages as seen when focusing the
-                        // window, then on scroll to bottom as usual
-                        threadWindow.$('.o_mail_thread, .o_thread_composer')
-                            .one('click', function () {
-                                thread.markAsRead();
-                            });
-                    } else if (
-                        !self._areThreadWindowsHidden() &&
-                        !thread.isFolded()
+                    threadWindow.scrollToBottom();
+                    if (
+                        !self._areAllThreadWindowsHidden() &&
+                        !thread.isFolded() &&
+                        !threadWindow.isPassive()
                     ) {
                         thread.markAsRead();
                     }
@@ -170,6 +132,8 @@ MailManager.include({
      * @param {integer|string} threadID
      * @param {Object} options option to be applied on opening thread window, if
      *   the thread is detached
+     * @param {boolean} [options.passively=false] if set, the window will behave
+     *   passively.
      */
     updateThreadWindow: function (threadID, options) {
         var thread = this.getThread(threadID);
@@ -198,14 +162,14 @@ MailManager.include({
         this._threadWindows.splice(this._availableSlotsForThreadWindows-1, 0, threadWindow);
     },
     /**
-     * States whether the thread windows are hidden or not.
+     * States whether all the thread windows are hidden or not.
      * When discuss is open, the thread windows are hidden.
      *
      * @private
      * @returns {boolean}
      */
-    _areThreadWindowsHidden: function () {
-        return this._isDiscussOpen();
+    _areAllThreadWindowsHidden: function () {
+        return $(this.THREAD_WINDOW_APPENDTO).hasClass('o_no_thread_window');
     },
     /**
      * Close the thread window linked to the thread with ID `threadID`.
@@ -224,6 +188,15 @@ MailManager.include({
             threadWindow.destroy();
         }
     },
+    /**
+     * Close the blank thread window.
+     */
+    _closeBlankThreadWindow: function () {
+        var blankThreadWindow = this._getBlankThreadWindow();
+        if (blankThreadWindow) {
+            this._closeThreadWindow(blankThreadWindow.getID());
+        }
+    },
     /**
      * Compute the number of available slots to display thread windows on the
      * screen. This is based on the width of the screen, and the width of a
@@ -256,8 +229,8 @@ MailManager.include({
      * Get the blank thread window, which is the special thread window that has
      * no thread linked to it.
      *
-     * This is useful in case a DM window may replace the blank thread window,
-     * when we want to open a DM from the blank thread window.
+     * This is useful in case a DM chat window may replace the blank thread
+     * window, when we want to open a DM chat from the blank thread window.
      *
      * @private
      * @returns {mail.ThreadWindow|undefined} the "blank thread" window,
@@ -298,6 +271,40 @@ MailManager.include({
             return threadWindow.getID() === threadID;
         });
     },
+    /**
+     * @override
+     * @private
+     */
+    _initializeInternalState: function () {
+        this._super.apply(this, arguments);
+
+        this._availableSlotsForThreadWindows = 0;
+        this._hiddenThreadWindows = [];
+        // used to keep dropdown open when closing thread windows
+        this._keepHiddenThreadWindowsDropdownOpen = false;
+        this._spaceLeftForThreadWindows = 0;
+        this._threadWindows = [];
+        // jQuery element for the dropdown of hidden thread windows
+        // see _renderHiddenThreadWindowsDropdown
+        this._$hiddenThreadWindowsDropdown = null;
+    },
+    /**
+     * @override
+     * @private
+     */
+    _listenOnBuses: function () {
+        this._super.apply(this, arguments);
+        this._mailBus
+            .on('update_message', this, this._onUpdateMessage)
+            .on('new_message', this, this._onNewMessage)
+            .on('new_channel', this, this._onNewChannel)
+            .on('is_thread_bottom_visible', this, this._onIsThreadBottomVisible)
+            .on('unsubscribe_from_channel', this, this._onUnsubscribeFromChannel)
+            .on('update_thread_unread_counter', this, this._onUpdateThreadUnreadCounter)
+            .on('update_dm_presence', this, this._onUpdateDmPresence);
+
+        core.bus.on('resize', this, _.debounce(this._repositionThreadWindows.bind(this), 100));
+    },
     /**
      * Make the hidden thread window dropdown menu, that is render it and set
      * event listener on this dropdown menu DOM element.
@@ -371,16 +378,16 @@ MailManager.include({
         threadWindow.toggleFold(false);
     },
     /**
-     * Open and detach the DM in a thread window.
+     * Open and detach the DM chat in a thread window.
      *
-     * This method assumes that no such DM exists locally, so it is kind of a
-     * "create DM and open DM window" operation
+     * This method assumes that no such DM chat exists locally, so it is kind
+     * of a "create DM chat and open DM chat window" operation
      *
      * @private
      * @param {integer} partnerID
-     * @returns {$.Promise<integer>} resolved with ID of the dm channel
+     * @returns {$.Promise<integer>} resolved with ID of the DM chat
      */
-    _openAndDetachDm: function (partnerID) {
+    _openAndDetachDMChat: function (partnerID) {
         return this._rpc({
             model: 'mail.channel',
             method: 'channel_get_and_minimize',
@@ -497,7 +504,7 @@ MailManager.include({
      * @private
      */
     _repositionThreadWindows: function () {
-        if (this._areThreadWindowsHidden()) {
+        if (this._areAllThreadWindowsHidden()) {
             return;
         }
         this._computeAvailableSlotsForThreadWindows(this._threadWindows.length);
@@ -532,28 +539,21 @@ MailManager.include({
      *
      * @private
      * @param {mail.model.Message} message
-     * @param {boolean} [scrollBottom=false] if set, thread windows with this
-     *   message should scroll to the bottom if the message is visible
+     * @param {Object} options
+     * @param {boolean} [options.keepBottom=false] if set, thread windows with
+     *   this message should scroll to the bottom if their bottoms are currently
+     *   visible.
+     * @param {boolean} [options.passively=false] if set, thread windows with
+     *   this message become passive, so that they are marked as read only when
+     *   the focus is on the thread window.
      */
-    _updateThreadWindows: function (message, scrollBottom) {
-        var self = this;
+    _updateThreadWindowsFromMessage: function (message, options) {
+        if (this._areAllThreadWindowsHidden()) {
+            return;
+        }
         _.each(this._threadWindows, function (threadWindow) {
             if (_.contains(message.getThreadIDs(), threadWindow.getID())) {
-                var thread = self.getThread(threadWindow.getID());
-                var messageVisible = !self._areThreadWindowsHidden() &&
-                                        !threadWindow.isFolded() &&
-                                        !threadWindow.isHidden() &&
-                                        threadWindow.threadWidget.isAtBottom();
-                if (messageVisible && !threadWindow.isPassive()) {
-                    thread.markAsRead();
-                }
-                thread.fetchMessages()
-                    .then(function () {
-                        threadWindow.render();
-                        if (scrollBottom && messageVisible) {
-                            threadWindow.threadWidget.scrollToBottom();
-                        }
-                    });
+                threadWindow.update(options);
             }
         });
     },
@@ -562,6 +562,14 @@ MailManager.include({
     // Handlers
     //--------------------------------------------------------------------------
 
+    /**
+     * Called when manually closing the blank thread window.
+     *
+     * @private
+     */
+    _onCloseBlankThreadWindow: function () {
+        this._closeBlankThreadWindow();
+    },
     /**
      * @private
      * @param {boolean} open
@@ -579,21 +587,21 @@ MailManager.include({
     /**
      * Called when someone asks window manager whether the bottom of `thread` is
      * visible or not. An object `query` is provided in order to reponse on the
-     * key `isDisplayed`.
+     * key `isVisible`.
      *
      * @private
      * @param {mail.model.Thread} thread
      * @param {Object} query
-     * @param {boolean} query.isBottomVisible write on it
+     * @param {boolean} query.isVisible write on it
      */
     _onIsThreadBottomVisible: function (thread, query) {
         _.each(this._threadWindows, function (threadWindow) {
             if (
                 thread.getID() === threadWindow.getID() &&
-                threadWindow.threadWidget.isAtBottom() &&
+                threadWindow.isAtBottom() &&
                 !threadWindow.isHidden()
             ) {
-                query.isBottomVisible = true;
+                query.isVisible = true;
             }
         });
     },
@@ -617,7 +625,7 @@ MailManager.include({
      * @param {Object} message
      */
     _onNewMessage: function (message) {
-        this._updateThreadWindows(message, true);
+        this._updateThreadWindowsFromMessage(message, { keepBottom: true, passively: true });
     },
     /**
      * Close the thread window when unsusbscribe from a channel.
@@ -677,7 +685,7 @@ MailManager.include({
      * @param {Object} message
      */
     _onUpdateMessage: function (message) {
-        this._updateThreadWindows(message, false);
+        this._updateThreadWindowsFromMessage(message, { keepBottom: false });
     },
 
 });
diff --git a/addons/mail/static/src/js/systray/systray_activity_menu.js b/addons/mail/static/src/js/systray/systray_activity_menu.js
index d65bb7ff5db..900d3610042 100644
--- a/addons/mail/static/src/js/systray/systray_activity_menu.js
+++ b/addons/mail/static/src/js/systray/systray_activity_menu.js
@@ -132,9 +132,7 @@ var ActivityMenu = Widget.extend({
         });
     },
     /**
-     * When menu clicked update activity preview if counter updated
      * @private
-     * @param {MouseEvent} event
      */
     _onActivityMenuClick: function () {
         if (!this._isOpen()) {
diff --git a/addons/mail/static/src/js/systray/systray_messaging_menu.js b/addons/mail/static/src/js/systray/systray_messaging_menu.js
index 5552a80393e..600570e3584 100644
--- a/addons/mail/static/src/js/systray/systray_messaging_menu.js
+++ b/addons/mail/static/src/js/systray/systray_messaging_menu.js
@@ -7,6 +7,8 @@ var SystrayMenu = require('web.SystrayMenu');
 var Widget = require('web.Widget');
 var QWeb = core.qweb;
 
+var _t = core._t;
+
 /**
  * Menu item appended in the systray part of the navbar
  *
@@ -252,6 +254,7 @@ var MessagingMenu = Widget.extend({
             // we are opening the dropdown so update its content
             this._updatePreviews();
         }
+        this._updatePreviews();
     },
     /**
      * @private
diff --git a/addons/mail/static/src/js/thread_field.js b/addons/mail/static/src/js/thread_field.js
index a239481931b..a6609ce6d73 100644
--- a/addons/mail/static/src/js/thread_field.js
+++ b/addons/mail/static/src/js/thread_field.js
@@ -37,7 +37,7 @@ var ThreadField = AbstractField.extend({
         this.dp = new concurrency.DropPrevious();
 
         this._threadWidget = new ThreadWidget(this, {
-            displayOrder: ThreadWidget.ORDER.DESC,
+            displayOrder: ThreadWidget.ORDER.ASC,
             displayDocumentLinks: false,
             displayMarkAsRead: false,
             squashCloseMessages: false,
diff --git a/addons/mail/static/src/js/thread_widget.js b/addons/mail/static/src/js/thread_widget.js
index ab0dea1bece..c2d642d5dbe 100644
--- a/addons/mail/static/src/js/thread_widget.js
+++ b/addons/mail/static/src/js/thread_widget.js
@@ -12,8 +12,8 @@ var QWeb = core.qweb;
 var _t = core._t;
 
 var ORDER = {
-    ASC: 1,
-    DESC: -1,
+    ASC: 1, // visually, chronological order of thread from bottom to top
+    DESC: -1, // visually, chronological order of thread from top to bottom
 };
 
 var READ_MORE = _t("read more");
@@ -55,7 +55,7 @@ var ThreadWidget = Widget.extend({
         // options when the thread is enabled (e.g. can send message,
         // interact on messages, etc.)
         this._enabledOptions = _.defaults(options || {}, {
-            displayOrder: ORDER.ASC,
+            displayOrder: ORDER.DESC,
             displayMarkAsRead: true,
             displayStars: true,
             displayDocumentLinks: true,
@@ -78,20 +78,16 @@ var ThreadWidget = Widget.extend({
             loadMoreOnScroll: this._enabledOptions.loadMoreOnScroll,
         };
         this._selectedMessageID = null;
+        this._currentThreadID = null;
     },
-
     /**
      * @override
      */
     destroy: function () {
         clearInterval(this._updateTimestampsInterval);
     },
-
     /**
-     * @param {mail.model.AbstractMessage[]} messages list of messages of the
-     *   thread, ordered by increasing IDs (a higher ID means a more recent
-     *   message).
-     * @param {}
+     * @param {mail.model.AbstractThread} thread the thread to render.
      * @param {Object} [options]
      * @param {integer} [options.displayOrder=ORDER.ASC] order of displaying
      *    messages in the thread:
@@ -99,11 +95,18 @@ var ThreadWidget = Widget.extend({
      *      - ORDER.DESC: last message is at the top of the thread
      * @param {boolean} [options.displayLoadMore]
      * @param {boolean} [options.isCreateMode]
+     * @param {boolean} [options.scrollToBottom=false]
      * @param {boolean} [options.squashCloseMessages]
      */
     render: function (thread, options) {
         var self = this;
 
+        var shouldScrollToBottomAfterRendering = false;
+        if (this._currentThreadID === thread.getID() && this.isAtBottom()) {
+            shouldScrollToBottomAfterRendering = true;
+        }
+        this._currentThreadID = thread.getID();
+
         // copy so that reverse do not alter order in the thread object
         var messages = _.clone(thread.getMessages());
 
@@ -115,9 +118,6 @@ var ThreadWidget = Widget.extend({
             return message.getAttachments();
         })));
 
-        if (modeOptions.displayOrder === ORDER.DESC) {
-            messages.reverse();
-        }
         options = _.extend({}, modeOptions, options, {
             selectedMessageID: this._selectedMessageID,
         });
@@ -160,6 +160,11 @@ var ThreadWidget = Widget.extend({
             }
             prevMessage = message;
         });
+
+        if (modeOptions.displayOrder === ORDER.DESC) {
+            messages.reverse();
+        }
+
         this.$el.html(QWeb.render('mail.widget.Thread', {
             thread: thread,
             displayAuthorMessages: displayAuthorMessages,
@@ -175,6 +180,10 @@ var ThreadWidget = Widget.extend({
             self._insertReadMore($message);
         });
 
+        if (shouldScrollToBottomAfterRendering) {
+            this.scrollToBottom();
+        }
+
         if (!this._updateTimestampsInterval) {
             this.updateTimestampsInterval = setInterval(function () {
                 self._updateTimestamps();
@@ -368,11 +377,6 @@ var ThreadWidget = Widget.extend({
             });
         });
     },
-
-    //--------------------------------------------------------------------------
-    // Private
-    //--------------------------------------------------------------------------
-
     /**
      * @private
      * @param {Object} options
diff --git a/addons/mail/static/src/js/thread_windows/abstract_thread_window.js b/addons/mail/static/src/js/thread_windows/abstract_thread_window.js
index 8ec8aa84b31..ffed0e16a1f 100644
--- a/addons/mail/static/src/js/thread_windows/abstract_thread_window.js
+++ b/addons/mail/static/src/js/thread_windows/abstract_thread_window.js
@@ -33,10 +33,10 @@ var AbstractThreadWindow = Widget.extend({
     events: {
         'click .o_thread_window_close': '_onClickClose',
         'click .o_thread_window_title': '_onClickFold',
-        'click .o_thread_composer': '_onComposerClick',
+        'click .o_composer_text_field': '_onComposerClick',
         'click .o_mail_thread': '_onThreadWindowClicked',
-        'keydown .o_thread_composer': '_onKeydown',
-        'keypress .o_thread_composer': '_onKeypress',
+        'keydown .o_composer_text_field': '_onKeydown',
+        'keypress .o_composer_text_field': '_onKeypress',
     },
     /**
      * Children of this class must make use of `thread`, which is an object that
@@ -50,6 +50,7 @@ var AbstractThreadWindow = Widget.extend({
      *   thread window is linked to. If not set, it is the "blank" thread
      *   window.
      * @param {Object} [options={}]
+     * @param {mail.model.AbstractThread} [options.thread]
      */
     init: function (parent, thread, options) {
         this._super(parent);
@@ -65,16 +66,19 @@ var AbstractThreadWindow = Widget.extend({
         this._hidden = false;
         this._thread = thread || null;
 
+        this._debouncedOnScroll = _.debounce(this._onScroll.bind(this), 100);
+
         if (!this.hasThread()) {
             // internal fold state of thread window without any thread
             this._folded = false;
         }
     },
     start: function () {
+        var self = this;
         this.$input = this.$('.o_composer_text_field');
         this.$header = this.$('.o_thread_window_header');
 
-        this.threadWidget = new ThreadWidget(this, {
+        this._threadWidget = new ThreadWidget(this, {
             displayDocumentLinks: false,
             displayMarkAsRead: false,
             displayStars: this.options.displayStars,
@@ -89,7 +93,9 @@ var AbstractThreadWindow = Widget.extend({
             var margin_dir = _t.database.parameters.direction === "rtl" ? "margin-left" : "margin-right";
             this.$el.css(margin_dir, $.position.scrollbarWidth());
         }
-        var def = this.threadWidget.replace(this.$('.o_thread_window_content'));
+        var def = this._threadWidget.replace(this.$('.o_thread_window_content')).then(function () {
+            self._threadWidget.$el.on('scroll', self, self._debouncedOnScroll);
+        });
         return $.when(this._super(), def);
     },
     /**
@@ -125,8 +131,9 @@ var AbstractThreadWindow = Widget.extend({
      */
     close: function () {},
     /**
-     * Get the status of the thread, such as the im status of a DM ('online',
-     * 'offline', etc.). If this window has no thread, returns `undefined`.
+     * Get the status of the thread, such as the im status of a DM chat
+     * ('online', 'offline', etc.). If this window has no thread, returns
+     * `undefined`.
      *
      * @returns {string|undefined}
      */
@@ -172,6 +179,15 @@ var AbstractThreadWindow = Widget.extend({
     hasThread: function () {
         return !! this._thread;
     },
+    /**
+     * Tells whether the bottom of the thread in the thread window is visible
+     * or not.
+     *
+     * @returns {boolean}
+     */
+    isAtBottom: function () {
+        return this._threadWidget.isAtBottom();
+    },
     /**
      * State whether the related thread is folded or not. If there are no
      * thread related to this window, it means this is the "blank" thread
@@ -202,13 +218,22 @@ var AbstractThreadWindow = Widget.extend({
     isHidden: function () {
         return this._hidden;
     },
+    /**
+     * States whether the input of the thread window should be displayed or not.
+     * By default, any thread window with a thread needs a composer.
+     *
+     * @returns {boolean}
+     */
+    needsComposer: function () {
+        return this.hasThread();
+    },
     /**
      * Render the thread window
      */
     render: function () {
         this.renderHeader();
         if (this.hasThread()) {
-            this.threadWidget.render(this._thread, { displayLoadMore: false });
+            this._threadWidget.render(this._thread, { displayLoadMore: false });
         }
     },
     /**
@@ -223,6 +248,12 @@ var AbstractThreadWindow = Widget.extend({
         this.$header.html(
             QWeb.render('mail.AbstractThreadWindow.HeaderContent', options));
     },
+    /**
+     * Scroll to the bottom of the thread in the thread window
+     */
+    scrollToBottom: function () {
+        this._threadWidget.scrollToBottom();
+    },
     /**
      * Toggle the fold state of this thread window. Also update the fold state
      * of the thread model. If the boolean parameter `folded` is provided, it
@@ -244,7 +275,7 @@ var AbstractThreadWindow = Widget.extend({
      */
     updateVisualFoldState: function () {
         if (!this.isFolded()) {
-            this.threadWidget.scrollToBottom();
+            this._threadWidget.scrollToBottom();
             this._focusInput();
         }
         this._animateFold();
@@ -311,13 +342,22 @@ var AbstractThreadWindow = Widget.extend({
         return this._thread.getID();
     },
     /**
-     * Post a message on this thread window
+     * Post a message on this thread window, and auto-scroll to the bottom of
+     * the thread.
      *
-     * @abstract
      * @private
      * @param {Object} messageData
      */
-    _postMessage: function (messageData) {},
+    _postMessage: function (messageData) {
+        var self = this;
+        if (!this.hasThread()) {
+            return;
+        }
+        this._thread.postMessage(messageData)
+            .then(function () {
+                self._threadWidget.scrollToBottom();
+            });
+    },
     /**
      * Update the fold state of the thread.
      * This function is called when toggling the fold state of this window.
@@ -334,6 +374,13 @@ var AbstractThreadWindow = Widget.extend({
             this._folded = folded;
         }
     },
+    /**
+     * Warn other mail components that the unread counter has been updated
+     *
+     * @abstract
+     * @private
+     */
+    _warnUpdatedUnreadCounter: function () {},
 
     //--------------------------------------------------------------------------
     // Handlers
@@ -416,6 +463,14 @@ var AbstractThreadWindow = Widget.extend({
     _onKeypress: function (ev) {
         ev.stopPropagation(); // to prevent jquery's blockUI to cancel event
     },
+    /**
+     * @private
+     */
+    _onScroll: function () {
+        if (this.hasThread() && this.isAtBottom()) {
+            this._thread.markAsRead();
+        }
+    },
     /**
      * When a thread window is clicked on, we want to give the focus to the main
      * input. An exception is made when the user is selecting something.
diff --git a/addons/mail/static/src/js/thread_windows/thread_window.js b/addons/mail/static/src/js/thread_windows/thread_window.js
index 1ff9417d127..1d38ee338d3 100644
--- a/addons/mail/static/src/js/thread_windows/thread_window.js
+++ b/addons/mail/static/src/js/thread_windows/thread_window.js
@@ -16,7 +16,10 @@ var _t = core._t;
  */
 var ThreadWindow = AbstractThreadWindow.extend({
     template: 'mail.ThreadWindow',
+    custom_events: AbstractThreadWindow.prototype.custom_events,
     events: _.extend({}, AbstractThreadWindow.prototype.events, {
+        'click .o_mail_thread': '_onThreadWindowFocus',
+        'click .o_thread_composer': '_onThreadWindowFocus',
         'click .o_thread_window_expand': '_onClickExpand',
     }),
     /**
@@ -25,7 +28,8 @@ var ThreadWindow = AbstractThreadWindow.extend({
      * @override
      * @param {mail.Manager} parent
      * @param {mail.model.Thread} [thread = null] if not set, this is a "blank"
-     *   thread window. It lets us open a DM by providing the name of a chat.
+     *   thread window. It lets us open a DM chat by providing the name of a
+     *   user.
      * @param {Object} [options={}]
      * @param {boolean} [options.passively=false]
      */
@@ -34,11 +38,11 @@ var ThreadWindow = AbstractThreadWindow.extend({
 
         // don't automatically mark unread messages as seen when at the bottom
         // of the thread
-        this._passive = this.options.passively;
+        this._passive = this.options.passively || false;
 
         if (!this.hasThread()) {
             // remembered partner ID of "blank" thread window in order to be
-            // replaced with newly opened DM window
+            // replaced with newly opened DM chat window
             this.directPartnerID = null;
         }
     },
@@ -54,10 +58,11 @@ var ThreadWindow = AbstractThreadWindow.extend({
         var composerDef;
         if (!this.hasThread()) {
             this._startWithoutThread();
-        } else if (this._needsComposer()) {
+        } else if (this.needsComposer()) {
             var basicComposer = new BasicComposer(this, {
                 mentionPartnersRestricted: this._thread.getType() !== 'document_thread',
-                isMini: true
+                isMini: true,
+                thread: this._thread,
             });
             basicComposer.on('post_message', this, this._postMessage);
             basicComposer.once('input_focused', this, function () {
@@ -85,6 +90,8 @@ var ThreadWindow = AbstractThreadWindow.extend({
     close: function () {
         if (this.hasThread()) {
             this._thread.close();
+        } else {
+            this.trigger_up('close_blank_thread_window');
         }
     },
     /**
@@ -124,6 +131,24 @@ var ThreadWindow = AbstractThreadWindow.extend({
     isPassive: function () {
         return this._passive;
     },
+    /**
+     * States whether the input of the thread window should be displayed or not.
+     * This is based on the type of the thread:
+     *
+     * Do not display the input in the following cases:
+     *
+     *      - no thread related to this window
+     *      - window of a mailbox (temp: let us have mailboxes in window mode)
+     *      - window of a thread with mass mailing
+     *
+     * Any other threads show the input in the window.
+     *
+     * @override
+     * @returns {boolean}
+     */
+    needsComposer: function () {
+        return this._super() && !this._thread.isMassMailing();
+    },
     /**
      * Turn the thread window in active mode, so that when the bottom of the
      * thread is visible, it is automatically marked as read.
@@ -131,6 +156,42 @@ var ThreadWindow = AbstractThreadWindow.extend({
     removePassive: function () {
         this._passive = false;
     },
+    /**
+     * Set the thread window in passive mode, so that new received message will
+     * keep the thread window as unread until there is focus on the thread
+     * window.
+     */
+    setPassive: function () {
+        this._passive = true;
+    },
+    /**
+     * Update this thread window
+     *
+     * @param {Object} options
+     * @param {boolean} [options.keepBottom=false] if set, this thread window
+     *   should scroll to the bottom if it was at the bottom before update
+     * @param {boolean} [options.passively=false] if set, this thread window
+     *   becomes passive, so that it is marked as read only when the focus is
+     *   on it.
+     */
+    update: function (options) {
+        var self = this;
+        if (options.passively) {
+            this.setPassive();
+        }
+        var bottomVisible = !this.isFolded() &&
+                            !this.isHidden() &&
+                            this.isAtBottom();
+        if (bottomVisible && !this.isPassive()) {
+            this._thread.markAsRead();
+        }
+        this._thread.fetchMessages().then(function () {
+            self.render();
+            if (bottomVisible && options.keepBottom) {
+                self.scrollToBottom();
+            }
+        });
+    },
 
     //--------------------------------------------------------------------------
     // Private
@@ -155,31 +216,11 @@ var ThreadWindow = AbstractThreadWindow.extend({
      * @private
      */
     _listenThreadWidget: function () {
-        this.threadWidget
+        this._threadWidget
             .on('redirect', this, this._onRedirect)
             .on('redirect_to_channel', this, this._onRedirectToChannel)
             .on('toggle_star_status', this, this._onToggleStarStatus);
     },
-    /**
-     * States whether the input of the thread window should be displayed or not.
-     * This is based on the type of the thread:
-     *
-     * Do not display the input in the following cases:
-     *
-     *      - no thread related to this window
-     *      - window of a mailbox (temp: let us have mailboxes in window mode)
-     *      - window of a thread with mass mailing
-     *
-     * Any other threads show the input in the window.
-     *
-     * @private
-     * @returns {boolean}
-     */
-    _needsComposer: function () {
-        return this.hasThread() &&
-                (this._thread.getType() !== 'mailbox') &&
-                !this._thread.isMassMailing();
-    },
     /**
      * Open this thread window.
      * This private method exists only for the purpose of providing a callback
@@ -190,24 +231,6 @@ var ThreadWindow = AbstractThreadWindow.extend({
     _open: function () {
         this.call('mail_service', 'openThreadWindow', this.getID());
     },
-    /**
-     * Post a message in the thread related to this window.
-     * If this window has no thread, do nothing
-     *
-     * @override
-     * @private
-     * @param {Object} messageData
-     */
-    _postMessage: function (messageData) {
-        var self = this;
-        if (!this.hasThread()) {
-            return;
-        }
-        this._thread.postMessage(messageData)
-            .then(function () {
-                self.threadWidget.scrollToBottom();
-            });
-    },
     /**
      * @private
      */
@@ -222,10 +245,10 @@ var ThreadWindow = AbstractThreadWindow.extend({
                 },
                 select: function (event, ui) {
                     // remember partner ID so that we can replace this window
-                    // with new DM window
+                    // with new DM chat window
                     var partnerID = ui.item.id;
                     self.directPartnerID = partnerID;
-                    self.call('mail_service', 'openDmWindow', partnerID);
+                    self.call('mail_service', 'openDMChatWindowFromBlankThreadWindow', partnerID);
                 },
             })
             .focus();
@@ -248,7 +271,7 @@ var ThreadWindow = AbstractThreadWindow.extend({
     _onClickExpand: _.debounce(function (ev) {
         var self = this;
         ev.preventDefault();
-        if (this._thread.getType() === 'document_thread') {
+        if (this.hasThread() && this._thread.getType() === 'document_thread') {
             this.do_action({
                 type: 'ir.actions.act_window',
                 res_model: this._thread.getDocumentModel(),
@@ -305,6 +328,30 @@ var ThreadWindow = AbstractThreadWindow.extend({
             this.toggleFold(false);
         }
     },
+    /**
+     * Override it so that passive thread windows do not mark thread as read
+     * on scroll
+     *
+     * @override
+     * @private
+     */
+    _onScroll: function () {
+        if (this.isPassive()) {
+            return;
+        }
+        return this._super.apply(this, arguments);
+    },
+    /**
+     * Called when focusing the thread window (click on thread or composer)
+     *
+     * @private
+     */
+    _onThreadWindowFocus: function () {
+        if (this.isPassive()) {
+            this.removePassive();
+            this._thread.markAsRead();
+        }
+    },
     /**
      * @private
      * @param {integer} messageID
diff --git a/addons/mail/static/src/scss/abstract_thread_window.scss b/addons/mail/static/src/scss/abstract_thread_window.scss
index 127b7b8adaf..9f0293ac3c0 100644
--- a/addons/mail/static/src/scss/abstract_thread_window.scss
+++ b/addons/mail/static/src/scss/abstract_thread_window.scss
@@ -75,6 +75,7 @@ $o-mail-thread-window-zindex: $zindex-modal + 1 !default;
         flex: 1 1 auto;
         overflow: auto;
         -webkit-overflow-scrolling: touch; // smooth scrolling in iOS app (Safari)
+
         .o_thread_date_separator {
             margin: 0px 0px 15px 0px;
             .o_thread_date {
diff --git a/addons/mail/static/src/scss/discuss.scss b/addons/mail/static/src/scss/discuss.scss
index cf037edd6f2..a1ae5482c65 100644
--- a/addons/mail/static/src/scss/discuss.scss
+++ b/addons/mail/static/src/scss/discuss.scss
@@ -127,7 +127,6 @@
         .o_mail_thread {
             flex: 1 0 0;
             overflow: auto;
-            padding: 0 0 15px 0;
             -webkit-overflow-scrolling: touch; // smooth scrolling in iOS app (Safari)
         }
 
diff --git a/addons/mail/static/src/scss/thread.scss b/addons/mail/static/src/scss/thread.scss
index b724c7fb241..12bd5a3af70 100644
--- a/addons/mail/static/src/scss/thread.scss
+++ b/addons/mail/static/src/scss/thread.scss
@@ -3,6 +3,37 @@
         text-align: center;
     }
 
+    .o_thread_bottom_free_space {
+        height: 15px;
+    }
+
+    .o_thread_tooltip_container {
+        display: inline;
+        position: relative;
+
+        .o_thread_tooltip_content {
+            top: 10px;
+            background: $gray-lighter;
+            padding: 4px;
+            border: solid $gray-lighter 1px;
+            border-radius: 5px;
+            color: gray;
+            width: 300px;
+            display: none;
+            opacity: 0;
+            position: absolute;
+            transition: opacity 0.5s;
+            i.fa-exclamation {
+                color: red;
+            }
+        }
+
+        .o_thread_tooltip:hover + .o_thread_tooltip_content {
+            display: inline;
+            opacity: 1;
+        }
+    }
+
     .o_thread_date_separator {
         margin-top: 15px;
         margin-bottom: 30px;
diff --git a/addons/mail/static/src/xml/abstract_thread_window.xml b/addons/mail/static/src/xml/abstract_thread_window.xml
index e62cdba042b..af72d5dd36c 100644
--- a/addons/mail/static/src/xml/abstract_thread_window.xml
+++ b/addons/mail/static/src/xml/abstract_thread_window.xml
@@ -15,7 +15,7 @@
             </div>
             <div class="o_thread_window_content">
             </div>
-            <div t-if='widget.hasThread()' class="o_thread_composer o_chat_mini_composer">
+            <div t-if="widget.needsComposer()" class="o_thread_composer o_chat_mini_composer">
                 <input class="o_composer_text_field" t-att-placeholder="widget.options.placeholder"/>
             </div>
         </div>
diff --git a/addons/mail/static/src/xml/discuss.xml b/addons/mail/static/src/xml/discuss.xml
index ad9a809ba03..eb03e3c0c55 100644
--- a/addons/mail/static/src/xml/discuss.xml
+++ b/addons/mail/static/src/xml/discuss.xml
@@ -40,7 +40,7 @@
                 <t t-set="counter" t-value="starredCounter"/>
                 <t t-call="mail.discuss.SidebarCounter"/>
             </div>
-            <div t-if="isModerator" t-attf-class="o_mail_discuss_title_main o_mail_discuss_item #{(activeThreadID == 'mailbox_moderation') ? 'o_active': ''}"
+            <div t-if="isMyselfModerator" t-attf-class="o_mail_discuss_title_main o_mail_discuss_item #{(activeThreadID == 'mailbox_moderation') ? 'o_active': ''}"
                  data-thread-id="mailbox_moderation">
                 <span class="o_thread_name"> <i class="fa fa-envelope mr8"/>Moderation Queue</span>
                 <t t-set="counter" t-value="moderationCounter"/>
@@ -58,7 +58,7 @@
                 <t t-set="inputPlaceholder">Add a channel</t>
             </t>
 
-            <t t-set="type" t-value="'dm'"/>
+            <t t-set="type" t-value="'dm_chat'"/>
             <t t-call="mail.discuss.SidebarTitle">
                 <t t-set="title">Direct Messages</t>
                 <t t-set="icon" t-value="fa-user"/>
@@ -133,7 +133,7 @@
             <input type="text" class="o_input" t-attf-placeholder="#{inputPlaceholder}"/>
         </div>
         <t t-foreach="threads" t-as="thread">
-            <t t-set="counter" t-value="thread.getType() === 'mailbox' ? thread.getMailboxCounter() : thread.isChat() ? thread.getUnreadCounter() : thread.getNeedactionCounter()"/>
+            <t t-set="counter" t-value="thread.getType() === 'mailbox' ? thread.getMailboxCounter() : thread.isTwoUserThread() ? thread.getUnreadCounter() : thread.getNeedactionCounter()"/>
             <div t-if="thread.getType() === type" t-att-data-thread-id="thread.getID()" t-att-title="thread.getName()"
                  t-attf-class="o_mail_discuss_item #{thread.hasUnreadMessages() ? ' o_unread_message' : ''} #{(activeThreadID == thread.getID()) ? 'o_active': ''}">
                 <span class="o_thread_name">
@@ -221,7 +221,7 @@
                     <span class="fa fa-inbox"/>
                     <span class="o_tab_title">Inbox</span>
                 </div>
-                <div class="o_mail_mobile_tab" data-type="dm">
+                <div class="o_mail_mobile_tab" data-type="dm_chat">
                     <span class="fa fa-user"/>
                     <span class="o_tab_title">Chat</span>
                 </div>
@@ -246,7 +246,7 @@
             <div t-if="!disableAddThread" class="o_mail_add_thread" t-att-data-type="type">
                 <span t-if="type == 'private' || type == 'public'">#</span>
                 <t t-set="inputPlaceholder" t-if="type == 'private' || type == 'public'">Add a channel</t>
-                <t t-set="inputPlaceholder" t-if="type == 'dm'">Open chat</t>
+                <t t-set="inputPlaceholder" t-if="type == 'dm_chat'">Open chat</t>
                 <input type="text" t-attf-placeholder="#{inputPlaceholder}"/>
             </div>
             <t t-foreach="previews" t-as="preview">
@@ -266,7 +266,7 @@
         @param {string} [preview.documentModel]
         @param {string|integer} preview.id
         @param {string} [preview.imageSRC]
-        @param {boolean} [preview.isAuthor]
+        @param {boolean} [preview.isMyselfAuthor]
         @param {moment} [preview.date]
         @param {string} [preview.author]
         @param {string} [preview.body]
@@ -293,7 +293,7 @@
                     <span class="o_last_message_date"> <t t-esc="preview.date ? preview.date.fromNow() : ''"/> </span>
                 </div>
                 <div t-if="preview.body" class="o_last_message_preview">
-                    <t t-if="preview.isAuthor">
+                    <t t-if="preview.isMyselfAuthor">
                         <span class="fa fa-mail-reply" role="img" aria-label="Reply"/> You:
                     </t>
                     <t t-elif="preview.author">
diff --git a/addons/mail/static/src/xml/thread.xml b/addons/mail/static/src/xml/thread.xml
index b3443418c2b..b33452382ac 100644
--- a/addons/mail/static/src/xml/thread.xml
+++ b/addons/mail/static/src/xml/thread.xml
@@ -3,22 +3,13 @@
 
     <!--
         @param {mail.model.AbstractThread} thread
+        @param {Object} options
         @param {boolean} [options.displayEmptyThread]
-        @param {boolean} [options.displayLoadMore]
         @param {boolean} [options.displayNoMatchFound]
-        @param {integer} [options.displayOrder] 1 or -1
-        @param {Object} ORDER
-        @param {integer} ORDER.ASC=1
-        @param {integer} ORDER.DESC=-1
     -->
     <t t-name="mail.widget.Thread">
         <t t-if="thread.hasMessages()">
-            <t t-set="messages" t-value="thread.getMessages()"/>
-            <t t-if="options.displayLoadMore and options.displayOrder == ORDER.ASC"
-               t-call="mail.widget.Thread.LoadMore"/>
             <t t-call="mail.widget.Thread.Content"/>
-            <t t-if="options.displayLoadMore and options.displayOrder == ORDER.DESC"
-               t-call="mail.widget.Thread.LoadMore"/>
         </t>
         <t t-elif="options.displayEmptyThread">
             <t t-call="mail.widget.Thread.Empty" />
@@ -134,14 +125,90 @@
     </div>
 
     <!--
-        @param {mail.model.AbstractMessage[]} messages messages ordered by increasing IDs
-        @param {string|integer} [options.messagesSeparatorPosition] 'top' or
-            message ID, the separator is placed just after this message.
+        @param {mail.model.AbstractThread} thread
+        @param {Object} options
+        @param {integer} [options.displayOrder] 1 or -1 chronological order for the thread messages
+        @param {Object} ORDER
+        @param {integer} ORDER.ASC=1 messages are ordered by increasing IDs, from bottom to top
+        @param {integer} ORDER.DESC=-1 messages are ordered by increasing IDs, from top to bottom
+
+        Ordering of messages in the thread, messages are indexed by increasing IDs:
+                    _____________            _____________
+                   |             |          |             |
+                   |  message 1  |          |  message n  |
+                   |  message 2  |          |  ...        |
+                   |  ...        |          |  message 2  |
+                   |  message n  |          |  message 1  |
+                   |_____________|          |_____________|
+
+        ORDER:           DESC                    ASC
+
     -->
     <t t-name="mail.widget.Thread.Content">
-        <t t-if="options.messagesSeparatorPosition == 'top'" t-call="mail.MessagesSeparator"/>
+        <t t-set="messages" t-value="thread.getMessages()"/>
+        <t t-if="options.displayOrder === ORDER.ASC" t-call="mail.widget.Thread.Content.ASC"/>
+        <t t-else="" t-call="mail.widget.Thread.Content.DESC"/>
+    </t>
+
+    <!--
+        @param {mail.model.AbstractThread} thread
+        @param {Object} options
+        @param {boolean} [options.displayLoadMore=false]
+        @param {string|integer} [options.messagesSeparatorPosition] 'top' or
+            message ID, the separator is placed just after this message.
+
+                     _____________
+                    |             |
+                    |  message n  |
+                    |  ...        |
+                    |  message 2  |
+                    |  message 1  |
+                    |_____________|
+
+                      ASC Order
+
+    -->
+    <t t-name="mail.widget.Thread.Content.ASC">
+        <div class="o_mail_thread_content_asc">
+            <t t-if="options.messagesSeparatorPosition == 'top'" t-call="mail.MessagesSeparator"/>
+            <t t-set="messages" t-value="messages.slice().reverse()"/>
+            <t t-call="mail.widget.Thread.Messages"/>
+            <t t-if="options.displayLoadMore" t-call="mail.widget.Thread.LoadMore"/>
+        </div>
+    </t>
+
+    <!--
+        @param {mail.model.AbstractThread} thread
+        @param {Object} options
+        @param {boolean} [options.displayBottomThreadFreeSpace=false]
+        @param {boolean} [options.displayLoadMore=false]
+
+                     _____________
+                    |             |
+                    |  message 1  |
+                    |  message 2  |
+                    |  ...        |
+                    |  message n  |
+                    |_____________|
+
+                      DESC Order
+    -->
+    <t t-name="mail.widget.Thread.Content.DESC">
+        <div class="o_mail_thread_content_desc">
+            <t t-if="options.displayLoadMore" t-call="mail.widget.Thread.LoadMore"/>
+            <t t-call="mail.widget.Thread.Messages"/>
+            <t t-if="options.displayBottomThreadFreeSpace">
+                <div class="o_thread_bottom_free_space"/>
+            </t>
+        </div>
+    </t>
+
+    <!--
+        @param {mail.model.AbstractMessage[]} messages messages are ordered based
+          on desired display order
+    -->
+    <t t-name="mail.widget.Thread.Messages">
         <t t-set="current_day" t-value="0"/>
-        <t t-if="options.displayOrder === ORDER.DESC" t-set="messages" t-value="messages.slice().reverse()"/>
         <t t-foreach="messages" t-as="message">
             <div t-if="current_day !== message.getDateDay()" class="o_thread_date_separator">
                 <span class="o_thread_date">
@@ -261,7 +328,7 @@
                             <t t-if="message.needsModerationByUser()">
                                 <t t-call="mail.MessageModerationDecision"/>
                             </t>
-                            <t t-elif="message.isAuthor()">
+                            <t t-elif="message.isMyselfAuthor()">
                                 <t t-call="mail.MessageModerationFeedback"/>
                             </t>
                         </t>
diff --git a/addons/mail/static/tests/discuss_mobile_tests.js b/addons/mail/static/tests/discuss_mobile_tests.js
index 82bcad30fe0..a0b9383ea45 100644
--- a/addons/mail/static/tests/discuss_mobile_tests.js
+++ b/addons/mail/static/tests/discuss_mobile_tests.js
@@ -47,9 +47,9 @@ QUnit.test('mobile basic rendering', function (assert) {
             "should be in inbox");
 
         // move to DMs tab
-        discuss.$('.o_mail_mobile_tab[data-type=dm]').click();
-        assert.ok(discuss.$('.o_mail_mobile_tab[data-type=dm]').hasClass('active'),
-            "should be in DMs tab");
+        discuss.$('.o_mail_mobile_tab[data-type=dm_chat]').click();
+        assert.ok(discuss.$('.o_mail_mobile_tab[data-type=dm_chat]').hasClass('active'),
+            "should be in DMs chat tab");
         assert.strictEqual(discuss.$('.o_mail_discuss_content .o_mail_no_content').length, 0,
             "should display the no content message");
         $('.o_mail_discuss_button_dm').click(); // click to add a channel
diff --git a/addons/mail/static/tests/discuss_moderation_tests.js b/addons/mail/static/tests/discuss_moderation_tests.js
index e324decba8c..505cb22aed4 100644
--- a/addons/mail/static/tests/discuss_moderation_tests.js
+++ b/addons/mail/static/tests/discuss_moderation_tests.js
@@ -6,7 +6,7 @@ var mailTestUtils = require('mail.testUtils');
 var createDiscuss = mailTestUtils.createDiscuss;
 
 QUnit.module('mail', {}, function () {
-QUnit.module('Discuss moderation', {
+QUnit.module('Discuss (Moderation)', {
     beforeEach: function () {
         // patch _.debounce and _.throttle to be fast and synchronous
         this.underscoreDebounce = _.debounce;
@@ -196,7 +196,7 @@ QUnit.test('moderator: moderated channel with pending moderation message', funct
         assert.strictEqual($(moderateAllSelector + '[data-decision="accept"]').length, 1,
             "there should one moderate button to accept messages pending moderation");
         assert.strictEqual($(moderateAllSelector + '[data-decision="accept"]').attr('style'),
-            'display: none;', 'the moderate button "Accept" should be invisible by default');
+            'display: none', 'the moderate button "Accept" should be invisible by default');
         assert.strictEqual($(moderateAllSelector + '[data-decision="reject"]').length, 1,
             "there should one moderate button to reject messages pending moderation");
         assert.strictEqual($(moderateAllSelector + '[data-decision="reject"]').attr('style'),
@@ -217,11 +217,11 @@ QUnit.test('moderator: moderated channel with pending moderation message', funct
             "the 'Unselect All' button should not be disabled");
         // check moderate all buttons updated (visible)
         assert.strictEqual($(moderateAllSelector + '[data-decision="accept"]').attr('style'),
-            'display: inline-block;', 'the moderate button "Accept" should become visible');
+            'display: inline-block', 'the moderate button "Accept" should become visible');
         assert.strictEqual($(moderateAllSelector + '[data-decision="reject"]').attr('style'),
-            'display: inline-block;', 'the moderate button "Reject" should become visible');
+            'display: inline-block', 'the moderate button "Reject" should become visible');
         assert.strictEqual($(moderateAllSelector + '[data-decision="discard"]').attr('style'),
-            'display: inline-block;', 'the moderate button "Discard" should become visible');
+            'display: inline-block', 'the moderate button "Discard" should become visible');
 
         // 2. go to channel 'general'
         discuss.$('.o_mail_discuss_item[data-thread-id="1"]').click();
diff --git a/addons/mail/static/tests/discuss_tests.js b/addons/mail/static/tests/discuss_tests.js
index 57a8c00ab26..6f605d24680 100644
--- a/addons/mail/static/tests/discuss_tests.js
+++ b/addons/mail/static/tests/discuss_tests.js
@@ -11,7 +11,6 @@ var testUtils = require('web.test_utils');
 var createDiscuss = mailTestUtils.createDiscuss;
 
 QUnit.module('mail', {}, function () {
-
 QUnit.module('Discuss', {
     beforeEach: function () {
         // patch _.debounce and _.throttle to be fast and synchronous
@@ -181,7 +180,7 @@ QUnit.test('@ mention in channel', function (assert) {
                     body: args.kwargs.body,
                     channel_ids: [1],
                 };
-                var notification = [[false, 'mail.channel'], data];
+                var notification = [[false, 'mail.channel', 1], data];
                 objectDiscuss.call('bus_service', 'trigger', 'notification', [notification]);
                 receiveMessageDef.resolve();
                 return $.when(42);
@@ -204,7 +203,6 @@ QUnit.test('@ mention in channel', function (assert) {
         var $input = discuss.$('textarea.o_composer_text_field').first();
         assert.ok($input.length, "should display a composer input");
 
-        // Simulate '@' typed by user with mocked Window.getSelection
         // Note: focus is needed in order to trigger rpc 'channel_fetch_listeners'
         $input.focus();
         $input.val("@");
@@ -309,7 +307,6 @@ QUnit.test('@ mention in channel', function (assert) {
                         assert.strictEqual(discuss.$('.o_thread_message_content a').text(),
                             "@Admin", "should have correct mention link in the message content");
 
-                        // Restore window.getSelection
                         discuss.destroy();
                         done();
                 });
@@ -360,7 +357,7 @@ QUnit.test('no crash focusout emoji button', function (assert) {
 });
 
 QUnit.test('older messages are loaded on scroll', function (assert) {
-    assert.expect(3);
+    assert.expect(10);
     var done = assert.async();
 
     var fetchCount = 0;
@@ -394,10 +391,15 @@ QUnit.test('older messages are loaded on scroll', function (assert) {
         services: this.services,
         mockRPC: function (route, args) {
             if (args.method === 'message_fetch') {
+                assert.step(args.method);
                 fetchCount++;
                 // 1st fetch: inbox initial fetch
                 // 2nd fetch: general initial fetch
                 // 3rd fetch: general load more
+                if (fetchCount === 1) {
+                    assert.strictEqual(args.kwargs.limit, 30,
+                        "should ask to fetch 30 messages at most");
+                }
                 if (fetchCount === 3) {
                     loadMoreDef.resolve();
                 }
@@ -405,6 +407,10 @@ QUnit.test('older messages are loaded on scroll', function (assert) {
             return this._super.apply(this, arguments);
         },
     }).then(function (discuss) {
+
+        assert.verifySteps(['message_fetch'],
+            "should fetch messages once for needaction messages (Inbox)");
+
         var $general = discuss.$('.o_mail_discuss_item[data-thread-id=1]');
         assert.strictEqual($general.length, 1,
             "should have a channel item with id 1");
@@ -412,6 +418,9 @@ QUnit.test('older messages are loaded on scroll', function (assert) {
         // switch to 'general'
         $general.click();
 
+        assert.verifySteps(['message_fetch', 'message_fetch'],
+            "should fetch a second time for general channel messages (30 last messages)");
+
         assert.strictEqual(discuss.$('.o_thread_message').length, 30,
             "should display the 30 messages");
 
@@ -421,6 +430,8 @@ QUnit.test('older messages are loaded on scroll', function (assert) {
         loadMoreDef
             .then(concurrency.delay.bind(concurrency, 0))
             .then(function () {
+                assert.verifySteps(['message_fetch', 'message_fetch', 'message_fetch'],
+                    "should fetch a third time for general channel messages (5 remaining messages)");
                 assert.strictEqual(discuss.$('.o_thread_message').length, 35,
                     "all messages should now be loaded");
 
@@ -621,7 +632,6 @@ QUnit.test('confirm dialog when administrator leave (not chat) channel', functio
         discuss.destroy();
         done();
     });
-
 });
 
 QUnit.test('convert emoji sources to unicodes on message_post', function (assert) {
@@ -657,7 +667,7 @@ QUnit.test('convert emoji sources to unicodes on message_post', function (assert
                     body: args.kwargs.body,
                     channel_ids: [1],
                 };
-                var notification = [[false, 'mail.channel'], data];
+                var notification = [[false, 'mail.channel', 1], data];
                 objectDiscuss.call('bus_service', 'trigger', 'notification', [notification]);
                 receiveMessageDef.resolve();
                 return $.when(42);
@@ -691,6 +701,6 @@ QUnit.test('convert emoji sources to unicodes on message_post', function (assert
         });
         });
     });
-});
 
 });
+});
diff --git a/addons/mail/static/tests/document_thread_window_tests.js b/addons/mail/static/tests/document_thread_window_tests.js
index 14d50d593ba..ec6f97f0b49 100644
--- a/addons/mail/static/tests/document_thread_window_tests.js
+++ b/addons/mail/static/tests/document_thread_window_tests.js
@@ -8,7 +8,7 @@ var testUtils = require('web.test_utils');
 
 QUnit.module('mail', {}, function () {
 
-QUnit.module('DocumentThreadWindow', {
+QUnit.module('ThreadWindow (Document Thread)', {
     beforeEach: function () {
         var partnerID = 44;
         this.data = {
diff --git a/addons/mail/static/tests/helpers/mock_server.js b/addons/mail/static/tests/helpers/mock_server.js
index 16b588b07ec..cff4917465a 100644
--- a/addons/mail/static/tests/helpers/mock_server.js
+++ b/addons/mail/static/tests/helpers/mock_server.js
@@ -155,6 +155,9 @@ MockServer.include({
         if (args.method === 'channel_fetch_preview') {
             return $.when(this._mockChannelFetchPreview(args));
         }
+        if (args.method === 'channel_minimize') {
+            return $.when();
+        }
         if (args.method === 'channel_seen') {
             return $.when();
         }
@@ -173,7 +176,7 @@ MockServer.include({
         if (args.method === 'moderate') {
             return $.when(this._mockModerate(args));
         }
-        if (args.method === 'channel_minimize') {
+        if (args.method === 'set_message_done') {
             return $.when();
         }
         return this._super(route, args);
diff --git a/addons/mail/static/tests/helpers/test_utils.js b/addons/mail/static/tests/helpers/test_utils.js
index a6b0b67a037..033866522e6 100644
--- a/addons/mail/static/tests/helpers/test_utils.js
+++ b/addons/mail/static/tests/helpers/test_utils.js
@@ -6,7 +6,6 @@ var BusService = require('bus.BusService');
 var Discuss = require('mail.Discuss');
 var MailService = require('mail.Service');
 
-var AbstractService = require('web.AbstractService');
 var AbstractStorageService = require('web.AbstractStorageService');
 var Class = require('web.Class');
 var ControlPanel = require('web.ControlPanel');
@@ -67,6 +66,7 @@ var MockMailService = Class.extend({
         return BusService.extend({
             _poll: function () {}, // Do nothing
             isOdooFocused: function () { return true; },
+            updateOption: function () {},
         });
     },
     mail_service: function () {
diff --git a/addons/mail/static/tests/thread_window_tests.js b/addons/mail/static/tests/thread_window_tests.js
index a10bed3f1b0..d8faa8d6a37 100644
--- a/addons/mail/static/tests/thread_window_tests.js
+++ b/addons/mail/static/tests/thread_window_tests.js
@@ -8,9 +8,14 @@ var testUtils = require('web.test_utils');
 var Widget = require('web.Widget');
 
 QUnit.module('mail', {
-    beforeEach: function () {
+    beforeEach: function (assert) {
         var self = this;
 
+        this.BEFORE_EACH_ASSERTIONS_NUM = 1;
+
+        assert.strictEqual($('.o_thread_window').length, 0,
+            "should have no thread windows open before the test");
+
         // define channel to link to chat window
         this.data = {
             'mail.message': {
@@ -34,6 +39,8 @@ QUnit.module('mail', {
             var widget = new Widget();
 
             // in non-debug mode, append thread windows in qunit-fixture
+            // note that it does not hide thread window because it uses fixed
+            // position, and qunit-fixture uses absolute...
             if (params.debug) {
                 self.services.mail_service.prototype.THREAD_WINDOW_APPENDTO = 'body';
             } else {
@@ -50,10 +57,9 @@ QUnit.module('mail', {
     },
 }, function () {
 
-    QUnit.module('thread_window');
-
+    QUnit.module('ThreadWindow');
     QUnit.test('close thread window using ESCAPE key', function (assert) {
-        assert.expect(5);
+        assert.expect(5 + this.BEFORE_EACH_ASSERTIONS_NUM);
 
         var parent = this.createParent({
             data: this.data,
@@ -91,7 +97,7 @@ QUnit.module('mail', {
     });
 
     QUnit.test('thread window\'s input can still be focused when the UI is blocked', function (assert) {
-        assert.expect(2);
+        assert.expect(2 + this.BEFORE_EACH_ASSERTIONS_NUM);
 
         var parent = this.createParent({
             data: this.data,
@@ -124,7 +130,7 @@ QUnit.module('mail', {
     });
 
     QUnit.test('emoji popover should open correctly in thread windows', function (assert) {
-        assert.expect(1);
+        assert.expect(1 + this.BEFORE_EACH_ASSERTIONS_NUM);
 
         var parent = this.createParent({
             data: this.data,
@@ -147,5 +153,6 @@ QUnit.module('mail', {
             done();
         }, 0);
     });
+
 });
 });
diff --git a/addons/mail/views/mail_templates.xml b/addons/mail/views/mail_templates.xml
index 36899afcdb2..bda7c071a0c 100644
--- a/addons/mail/views/mail_templates.xml
+++ b/addons/mail/views/mail_templates.xml
@@ -24,13 +24,17 @@
                     <script type="text/javascript" src="/mail/static/src/js/models/messages/message.js"></script>
                     <!-- threads -->
                     <script type="text/javascript" src="/mail/static/src/js/models/threads/abstract_thread.js"></script>
-                    <script type="text/javascript" src="/mail/static/src/js/models/threads/channel.js"></script>
+                        <!-- channels -->
+                        <script type="text/javascript" src="/mail/static/src/js/models/threads/channel.js"></script>
+                        <script type="text/javascript" src="/mail/static/src/js/models/threads/multi_user_channel.js"></script>
+                        <script type="text/javascript" src="/mail/static/src/js/models/threads/two_user_channel.js"></script>
                     <script type="text/javascript" src="/mail/static/src/js/models/threads/create_mode_document_thread.js"></script>
-                    <script type="text/javascript" src="/mail/static/src/js/models/threads/dm.js"></script>
+                    <script type="text/javascript" src="/mail/static/src/js/models/threads/dm_chat.js"></script>
                     <script type="text/javascript" src="/mail/static/src/js/models/threads/document_thread.js"></script>
+                    <script type="text/javascript" src="/mail/static/src/js/models/threads/livechat.js"></script>
                     <script type="text/javascript" src="/mail/static/src/js/models/threads/mailbox.js"></script>
+                    <script type="text/javascript" src="/mail/static/src/js/models/threads/searchable_thread.js"></script>
                     <script type="text/javascript" src="/mail/static/src/js/models/threads/thread.js"></script>
-                    <script type="text/javascript" src="/mail/static/src/js/models/threads/thread_with_cache.js"></script>
                 <!-- Widgets -->
                     <!-- thread windows -->
                     <script type="text/javascript" src="/mail/static/src/js/thread_windows/abstract_thread_window.js"></script>