diff --git a/addons/mail/models/mail_channel.py b/addons/mail/models/mail_channel.py
index 31e03b99081..e9e9969a017 100644
--- a/addons/mail/models/mail_channel.py
+++ b/addons/mail/models/mail_channel.py
@@ -354,6 +354,11 @@ class Channel(models.Model):
                                           .channel_partner_ids
                                           .filtered(lambda p: p.id != self.env.user.partner_id.id)
                                           .read(['id', 'name', 'im_status']))
+
+            last_message = channel.channel_fetch_preview()
+            if last_message:
+                info['last_message'] = last_message[0].get('last_message')
+
             # add user session state, if available and if user is logged
             if partner_channels.ids:
                 partner_channel = partner_channels.filtered(lambda c: channel.id == c.channel_id.id)
diff --git a/addons/mail/static/src/js/chat_manager.js b/addons/mail/static/src/js/chat_manager.js
index 807d5352180..128309bc77d 100644
--- a/addons/mail/static/src/js/chat_manager.js
+++ b/addons/mail/static/src/js/chat_manager.js
@@ -82,6 +82,8 @@ function add_message (data, options) {
         _.each(msg.channel_ids, function (channel_id) {
             var channel = chat_manager.get_channel(channel_id);
             if (channel) {
+                // For mobile tabs view, we show recent message for channel. 
+                channel.last_message = msg;
                 add_to_cache(msg, []);
                 if (options.domain && options.domain !== []) {
                     add_to_cache(msg, options.domain);
@@ -288,6 +290,7 @@ function make_channel (data, options) {
         group_based_subscription: data.group_based_subscription,
         needaction_counter: data.message_needaction_counter || 0,
         unread_counter: 0,
+        last_message: data.last_message,
         last_seen_message_id: data.seen_message_id,
         cache: {'[]': {
             all_history_loaded: false,
diff --git a/addons/mail/static/src/js/chat_window.js b/addons/mail/static/src/js/chat_window.js
index 9f91baee764..9d54a6df0b2 100644
--- a/addons/mail/static/src/js/chat_window.js
+++ b/addons/mail/static/src/js/chat_window.js
@@ -11,7 +11,7 @@ var QWeb = core.qweb;
 var _t = core._t;
 
 var HEIGHT_OPEN = '400px';
-var HEIGHT_FOLDED = '28px';
+var HEIGHT_FOLDED = '34px';
 
 return Widget.extend({
     template: "mail.ChatWindow",
@@ -43,6 +43,7 @@ return Widget.extend({
         this.status = this.options.status;
         this.unread_msgs = unread_msgs || 0;
         this.is_hidden = false;
+        this.isMobile = config.isMobile;
     },
     start: function () {
         this.$input = this.$('.o_composer_text_field');
@@ -76,6 +77,13 @@ return Widget.extend({
         this.unread_msgs = counter;
         this.render_header();
     },
+
+    /**
+     * When user status (online/offline/away) changed, this method update
+     * user status with last seen and render header again.
+     *
+     * @param {string} status
+     */
     update_status: function (status) {
         this.status = status;
         this.render_header();
@@ -84,13 +92,14 @@ return Widget.extend({
         this.$header.html(QWeb.render('mail.ChatWindowHeaderContent', {
             status: this.status,
             title: this.title,
+            isMobile: this.isMobile,
             unread_counter: this.unread_msgs,
         }));
     },
     fold: function () {
         this.$el.animate({
             height: this.folded ? HEIGHT_FOLDED : HEIGHT_OPEN
-        });
+        }, 200);
     },
     toggle_fold: function (fold) {
         this.folded = _.isBoolean(fold) ? fold : !this.folded;
diff --git a/addons/mail/static/src/js/client_action.js b/addons/mail/static/src/js/client_action.js
index a27790f9629..4058fbc0924 100644
--- a/addons/mail/static/src/js/client_action.js
+++ b/addons/mail/static/src/js/client_action.js
@@ -16,6 +16,7 @@ var dom = require('web.dom');
 var pyeval = require('web.pyeval');
 var SearchView = require('web.SearchView');
 var Widget = require('web.Widget');
+var session = require('web.session');
 
 var QWeb = core.qweb;
 var _t = core._t;
@@ -149,10 +150,13 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
                 on_reverse_breadcrumb: this.on_reverse_breadcrumb,
             });
         },
+        "click .o_mail_chat_mobile_tab": '_onMobileTabClick',
+        "click .o_channel_inbox_item": '_onMobileChannelItemClick',
+        "click .o_mail_tab_pane_item": '_onMobileTabPaneItemClick',
     },
 
     on_attach_callback: function () {
-        chat_manager.bus.trigger('client_action_open', true);
+        chat_manager.bus.trigger('client_action_open', !this.isMobile);
         if (this.channel) {
             this.thread.scroll_to({offset: this.channels_scrolltop[this.channel.id]});
         }
@@ -174,6 +178,8 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
         this.notification_bar = (window.Notification && window.Notification.permission === "default");
         this.selected_message = null;
         this.composerStates = {};
+        this.isMobile = config.isMobile;
+        this.activeMobileTab = "channel_inbox";
     },
 
     willStart: function () {
@@ -196,29 +202,26 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
             action: this.action,
             disable_groupby: true,
         };
-        var default_channel_id = this.options.active_id ||
+        var defaultChannelId = this.options.active_id ||
                                  this.action.context.active_id ||
                                  this.action.params.default_active_id ||
                                  'channel_inbox';
-        var default_channel = chat_manager.get_channel(default_channel_id) ||
+        var defaultChannel = chat_manager.get_channel(defaultChannelId) ||
                               chat_manager.get_channel('channel_inbox');
-
+        this.activeMobileTab = defaultChannelId;
         this.searchview = new SearchView(this, this.dataset, this.fields_view, options);
 
         this.basic_composer = new composer.BasicComposer(this, {mention_partners_restricted: true});
         this.extended_composer = new composer.ExtendedComposer(this, {mention_partners_restricted: true});
         this.thread = new ChatThread(this, {
-            display_help: true,
+            display_help: true
         });
 
-        this.$buttons = $(QWeb.render("mail.chat.ControlButtons", {}));
+        this.$buttons = $(QWeb.render("mail.chat.ControlButtons", {'debug': session.debug}));
         this.$buttons.find('button').css({display:"inline-block"});
         this.$buttons.on('click', '.o_mail_chat_button_invite', this.on_click_button_invite);
         this.$buttons.on('click', '.o_mail_chat_button_unsubscribe', this.on_click_button_unsubscribe);
         this.$buttons.on('click', '.o_mail_chat_button_settings', this.on_click_button_settings);
-        this.$buttons.on('click', '.o_mail_toggle_channels', function () {
-            self.$('.o_mail_chat_sidebar').slideToggle(200);
-        });
         this.$buttons.on('click', '.o_mail_chat_button_mark_read', function () {
             chat_manager.mark_all_as_read(self.channel, self.domain);
         });
@@ -254,10 +257,13 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
             self.$searchview_buttons = self.searchview.$buttons.contents();
         });
 
+        if (this.isMobile) {
+            this._initMobileView();
+        }
         this.renderSidebar();
 
         return $.when(def1, def2, def3, def4)
-            .then(this.set_channel.bind(this, default_channel))
+            .then(this.set_channel.bind(this, defaultChannel))
             .then(function () {
                 chat_manager.bus.on('open_channel', self, self.set_channel);
                 chat_manager.bus.on('new_message', self, self.on_new_message);
@@ -309,7 +315,14 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
         this.selected_message = null;
     },
 
+    /**
+     * Rendering main side bar with channels
+     */
     renderSidebar: function () {
+        if (this.isMobile) {
+            this._renderTabPanes();
+        }
+
         var self = this;
         var $sidebar = this._renderSidebar({
             active_channel_id: this.channel ? this.channel.id: undefined,
@@ -452,27 +465,7 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
             }
 
             // Update control panel
-            self.set("title", '#' + channel.name);
-            // Hide 'unsubscribe' button in state channels and DM and channels with group-based subscription
-            self.$buttons
-                .find('.o_mail_chat_button_unsubscribe')
-                .toggle(channel.type !== "dm" && channel.type !== 'static' && ! channel.group_based_subscription);
-            // Hide 'invite', 'unsubscribe' and 'settings' buttons in static channels and DM
-            self.$buttons
-                .find('.o_mail_chat_button_invite, .o_mail_chat_button_settings')
-                .toggle(channel.type !== "dm" && channel.type !== 'static');
-            self.$buttons
-                .find('.o_mail_chat_button_mark_read')
-                .toggle(channel.id === "channel_inbox");
-            self.$buttons
-                .find('.o_mail_chat_button_unstar_all')
-                .toggle(channel.id === "channel_starred");
-
-            self.$('.o_mail_chat_channel_item')
-                .removeClass('o_active')
-                .filter('[data-channel-id=' + channel.id + ']')
-                .removeClass('o_unread_message')
-                .addClass('o_active');
+            self._updateControlPanelButtons(channel);
 
             var $new_messages_separator = self.$('.o_thread_new_messages_separator');
             if ($new_messages_separator.length) {
@@ -578,7 +571,23 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
                 $searchview_buttons: this.$searchview_buttons,
             },
             searchview: this.searchview,
+            hidden: this.isMobile
         });
+
+        if (this.isMobile) {
+            var self = this;
+            var $enable_searchview = $('<button/>', {type: 'button'})
+                .addClass('o_enable_searchview btn fa fa-search')
+                .on('click', function() {
+                    self.searchview_displayed = !self.searchview_displayed;
+                    self.searchview.$el.toggleClass('o_hidden', !self.searchview_displayed);
+                    self.$buttons.toggleClass('o_hidden', self.searchview_displayed);
+                });
+            this.$buttons.appendTo(this.mailMobileControlPanel);
+            this.searchview.$el.appendTo(this.mailMobileControlPanel);
+            this.$(".o_enable_searchview").remove();
+            $enable_searchview.insertAfter(this.searchview.$el);
+        }
     },
 
     do_show: function () {
@@ -657,7 +666,11 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
     on_new_channel: function (channel) {
         this.renderSidebar();
         if (channel.autoswitch) {
-            this.set_channel(channel);
+            if (this.isMobile) {
+                chat_manager.detach_channel(channel);
+            }else {
+                this.set_channel(channel);
+            }
         }
     },
     on_channel_unsubscribed: function (channel_id) {
@@ -697,10 +710,168 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
         this._super.apply(this, arguments);
     },
 
+    //--------------------------------------------------------------------------
+    // Private
+    //--------------------------------------------------------------------------
+
+     /**
+      * Initialize control panel, tabs and panel of tab for mobile
+      *
+      * @private
+      */
+    _initMobileView: function () {
+        this.mailMobileControlPanel = $(QWeb.render("mail.chat.MobileControlPanel",{'widget': this}));
+        this.mailMobileInboxButtons = $(QWeb.render("mail.chat.MobileInboxStarredButtons", {}));
+        var mailMobileTabs = $(QWeb.render("mail.chat.MobileTabs",{}));
+
+        this.$(".o_mail_chat_mobile_control_panel").remove();
+        this.mailMobileControlPanel.insertAfter(this.$(".o_mail_chat_content"));
+        this.mailMobileInboxButtons.insertAfter(this.mailMobileControlPanel);
+        mailMobileTabs.insertAfter(this.$('.o_mail_chat_content'));
+    },
+    /**
+     * Rendering mobile tab panes with channles and dm messages
+     *
+     * @private
+     */
+    _renderTabPanes: function () {
+        var channels = chat_manager.get_channels();
+        var paneChannels = [
+            {type: "dm", channels: _.where(channels, {type: "dm"})},
+            {type: "public", channels: _.where(channels, {type: "public"})},
+            {type: "private", channels: _.where(channels, {type: "private"})}
+        ];
+        var $tabPanes = $(QWeb.render("mail.chat.MobileTabPanes", {
+            channels: paneChannels,
+            moment: moment,
+            widget: this,
+            get_message_body_preview: chat_manager.get_message_body_preview
+        }));
+        this.$(".o_mail_chat_tab_pane").remove();
+        $tabPanes.insertAfter(this.$(".o_mail_chat_content"));
+
+        if (this.activeMobileTab == 'channel_inbox' || this.activeMobileTab == 'channel_starred') {
+            this._switchMobileTab(chat_manager.get_channel(this.activeMobileTab));
+        } else {
+            this._switchMobileTab(false, this.activeMobileTab);
+        }
+    },
+    /**
+     * Switching mobile tab and changing style state to active, also showing related tab pane
+     * for active channel tab
+     *
+     * @private
+     * @param {Object} channel
+     * @param {string} type     Value can be (channel_inbox, channel_starred, dm, public, private)
+     */
+    _switchMobileTab: function(channel, type) {
+        var title;
+        this.$(".o_mail_chat_tab_pane").hide();
+        this.$(".o_mail_chat_content").hide();
+        this.$(".o_mail_chat_buttons").find("button").addClass("o_hidden");
+        // Updating control panel buttons
+        this._updateControlPanelButtons(channel);
+        if (!type && channel) {
+            type = channel.id == 'channel_starred' ? 'channel_inbox' : channel.id;
+            title = "#" + channel.name;
+            this.$(".o_channel_inbox_item").removeClass("btn-primary").addClass("btn-default");
+            this.$(".o_channel_inbox_item[data-type=" + channel.id + "]").removeClass("btn-default").addClass("btn-primary");
+            this.$(".o_mail_chat_content").show();
+        } else {
+            this.$(".o_mail_chat_tab_pane[data-type=" + type + "]").show();
+            this.$(".o_mail_chat_button_" + type).removeClass("o_hidden");
+        }
+        this.$(".o_mail_chat_mobile_tab").removeClass('active');
+        this.$(".o_mail_chat_mobile_tab[data-type=" + type + "]").addClass('active');
+    },
+    /**
+     * Updating control panel buttons visibility based on channel type
+     *
+     * @private
+     * @param {Object} channel
+     */
+    _updateControlPanelButtons: function (channel) {
+        this.set("title", '#' + channel.name);
+        // Hide 'unsubscribe' button in state channels and DM and channels with group-based subscription
+        this.$buttons
+            .find('.o_mail_chat_button_unsubscribe')
+            .toggle(channel.type !== "dm" && channel.type !== 'static' && ! channel.group_based_subscription);
+        // Hide 'invite', 'unsubscribe' and 'settings' buttons in static channels and DM
+        this.$buttons
+            .find('.o_mail_chat_button_invite, .o_mail_chat_button_settings')
+            .toggle(channel.type !== "dm" && channel.type !== 'static');
+        this.$buttons
+            .find('.o_mail_chat_button_mark_read')
+            .toggle(channel.id === "channel_inbox")
+            .removeClass("o_hidden");
+        this.$buttons
+            .find('.o_mail_chat_button_unstar_all')
+            .toggle(channel.id === "channel_starred")
+            .removeClass("o_hidden");
+
+        this.$('.o_mail_chat_channel_item')
+            .removeClass('o_active')
+            .filter('[data-channel-id=' + channel.id + ']')
+            .removeClass('o_unread_message')
+            .addClass('o_active');
+    },
+
     //--------------------------------------------------------------------------
     // Handlers
     //--------------------------------------------------------------------------
 
+    /**
+     * @private
+     * @param {MouseEvent}
+     */
+    _onMobileChannelItemClick: function (event) {
+        event.preventDefault();
+        this.$(".o_channel_inbox_item").toggleClass("btn-primary btn-default");
+        var btn = this.$(event.currentTarget);
+        btn.addClass("btn-primary");
+        this.activeMobileTab = btn.data('type');
+        var channel = chat_manager.get_channel(this.activeMobileTab);
+        this._switchMobileTab(channel);
+        this.set_channel(channel);
+    },
+    /**
+     * @private
+     * @param {MouseEvent}
+     */
+    _onMobileTabClick: function (event) {
+        event.preventDefault();
+        var self = this;
+        var tab = this.$(event.currentTarget);
+        var type = tab.data('type');
+        this.activeMobileTab = type;
+        if (type == 'channel_inbox' || type == 'channel_starred') {
+            this.mailMobileInboxButtons.show();
+            var channel = chat_manager.get_channel(type);
+            this._switchMobileTab(channel);
+            this.set_channel(channel);
+        } else {
+            this.mailMobileInboxButtons.hide();
+            this._switchMobileTab(false, type);
+            var typeButton = $(".o_mail_chat_button_" + type);
+            if (typeButton) {
+                typeButton.off('click');
+                typeButton.on('click', function(event) {
+                    event.preventDefault();
+                    self.$(".o_mail_add_channel[data-type=" + type + "]").show()
+                        .find("input").focus();
+                });
+            }
+        }
+    },
+    /**
+     * @private
+     * @param {MouseEvent}
+     */
+    _onMobileTabPaneItemClick: function (event) {
+        event.preventDefault();
+        var channelId = $(event.currentTarget).data("channel-id");
+        chat_manager.detach_channel(chat_manager.get_channel(channelId));
+    },
     /**
      * @private
      * @param {OdooEvent}
@@ -716,7 +887,7 @@ var ChatAction = Widget.extend(ControlPanelMixin, {
     },
 });
 
-
 core.action_registry.add('mail.chat.instant_messaging', ChatAction);
 
+return ChatAction;
 });
diff --git a/addons/mail/static/src/js/composer.js b/addons/mail/static/src/js/composer.js
index 2782ff11442..f6773cc7256 100644
--- a/addons/mail/static/src/js/composer.js
+++ b/addons/mail/static/src/js/composer.js
@@ -6,6 +6,7 @@ var DocumentViewer = require('mail.DocumentViewer');
 var utils = require('mail.utils');
 
 var core = require('web.core');
+var config = require('web.config');
 var data = require('web.data');
 var dom = require('web.dom');
 var session = require('web.session');
@@ -374,6 +375,7 @@ var BasicComposer = Widget.extend(chat_mixin, {
             send_text: _t('Send'),
             default_body: '',
             default_mention_selections: {},
+            isMobile: config.isMobile
         });
         this.context = this.options.context;
 
diff --git a/addons/mail/static/src/js/systray.js b/addons/mail/static/src/js/systray.js
index 5995c635f33..24f2a247cf4 100644
--- a/addons/mail/static/src/js/systray.js
+++ b/addons/mail/static/src/js/systray.js
@@ -6,6 +6,7 @@ var framework = require('web.framework');
 var session = require('web.session');
 var SystrayMenu = require('web.SystrayMenu');
 var Widget = require('web.Widget');
+var config = require('web.config');
 
 var chat_manager = require('mail.chat_manager');
 
@@ -27,6 +28,10 @@ var MessagingMenu = Widget.extend({
         "click .o_new_message": "on_click_new_message",
         "click .o_mail_channel_preview": "_onClickChannel",
     },
+    init: function (parent) {
+        this.isMobile = config.isMobile;
+        this._super(parent);
+    },
     start: function () {
         this.$filter_buttons = this.$('.o_filter_button');
         this.$channels_preview = this.$('.o_mail_navbar_dropdown_channels');
diff --git a/addons/mail/static/src/less/chat_window.less b/addons/mail/static/src/less/chat_window.less
index 3e93945d194..bafe43e2974 100644
--- a/addons/mail/static/src/less/chat_window.less
+++ b/addons/mail/static/src/less/chat_window.less
@@ -1,7 +1,8 @@
-@o-chat-window-bg: white;
+@o-chat-window-bg: #FAFAFA;
 @o-chat-window-width: 325px;
 @o-mail-chatter-gap: 10px; // has to be defined here as this file is both in
                            // backend and other assets (livechat)
+@o-chat-header-height: 44px;
 
 .o_chat_window {
     .o-flex-display();
@@ -13,13 +14,14 @@
     max-height: 100%;
     font-size: 12px;
     background-color: @o-chat-window-bg;
-    border-radius: 3px 3px 0 0;
+    border-radius: 6px 6px 0 0;
     z-index: 3;
-    box-shadow: -5px -5px 20px fade(black, 28%);
+    box-shadow: -5px -5px 10px fade(black, 18%);
 
     @media (max-width: @screen-xs-max) {
         width: 100%;
         height: 100%!important;
+        box-shadow: none;
         &.o_folded {
             display: none;
         }
@@ -37,16 +39,26 @@
         border-radius: 3px 3px 0 0;
         border-bottom: 1px solid @odoo-color-silver-dark; // cannot use gray-lighter-dark as this file is also frontend
         background-color: @odoo-brand-primary;
+        padding: 8px;
 
         @media (max-width: @screen-xs-max) {
-            height: @navbar-height;
-            .o_chat_title, .o_chat_window_close {
-                font-size: 22px;
+            height: @o-chat-header-height;
+            padding-top: 10px;
+            border-radius: 0px;
+            .o_chat_title {
+                font-size: 16px;
+                margin-left: 10px;
+            }
+
+            .o_chat_window_close {
+                font-size: 17px;
+                color: white;
             }
         }
 
         .o_chat_title {
             cursor: pointer;
+            font-weight: bold;
             .o-flex(1, 1, auto);
             .o-text-overflow();
         }
@@ -68,20 +80,112 @@
         overflow: auto;
         border: 1px solid @odoo-color-silver-dark; // cannot use gray-lighter-dark as this file is also frontend
         border-width: 0 1px;
+        font-weight: 400;
 
         .o_thread_date_separator {
             margin-top: 0px;
-            margin-bottom: 15px;
-            border-color: lightgray;
+            margin-bottom: 25px;
+            border-bottom: 1px dashed #cccccc;
             .o_thread_date {
                 background-color: @o-chat-window-bg;
             }
         }
         .o_thread_message {
             .o_thread_message_sidebar {
-                margin-right: 5px;
+                margin-right: 10px;
+
+                .o_thread_message_avatar {
+                    border-radius: 4px;
+                    border: 1px solid #ebebeb;
+                    max-width: 40px;
+                }
             }
-            padding: 4px 5px;
+            padding: 4px 5px 0px 10px;
+
+            .o_mail_info {
+
+                .o_thread_author, strong a.o_mail_mailto, strong a.o_mail_mailto:hover {
+                    font-weight: 500;
+                    color: #111;
+                    font-size: 11px;
+                    @media (max-width: @screen-xs-max) {
+                        font-size: 13px;
+                    }
+                    margin-top: 5px;
+                }
+                .o_mail_timestamp {
+                    font-size: 11px;
+                    color: #aaa;
+                }
+
+                .o_thread_message_star {
+                    opacity: 1;
+                }
+
+                .o_document_link {
+                    display: block;
+                    max-width: 90%;
+                    font-size: 12px;
+                    @media (max-width: @screen-xs-max) {
+                        font-size: 14px;
+                    }
+                    white-space: nowrap;
+                    text-overflow: ellipsis;
+                    overflow: hidden;
+                    padding-bottom: 0px;
+                    font-weight: 500;
+                }
+            }
+
+            .o_thread_message_content {
+                font-size: 12px;
+                padding-right: 10px;
+                @media (max-width: @screen-xs-max) {
+                    font-size: 14px;
+                }
+                color: #333;
+                p {
+                    margin: 0px 0px 8px;
+                }
+                ul.o_mail_thread_message_tracking {
+                    padding-left: 20px;
+                }
+            }
+        }
+    }
+
+    .o_chat_composer {
+        .o-flex(0, 0, auto);
+        border-left: 1px solid #ebebeb;
+        border-right: 1px solid #ebebeb;
+
+        .o_composer_buttons > button {
+            border: none;
+        }
+
+        .o_composer_button {
+            display: none;
+        }
+
+        .o_composer_mobile_button {
+            display: none;
+        }
+
+
+        @media (max-width: @screen-xs-max) {
+            .o_composer_mobile_button {
+                display: inline-block;
+                background-color: @odoo-brand-optional;
+                color: #fff;
+            }
+        }
+
+        > input {
+            padding: 5px;
+            width: 100%;
+        }
+        .o_composer_input > textarea {
+            border-color: transparent;
         }
     }
 }
diff --git a/addons/mail/static/src/less/client_action.less b/addons/mail/static/src/less/client_action.less
index 78a4f27f21b..367e791295a 100644
--- a/addons/mail/static/src/less/client_action.less
+++ b/addons/mail/static/src/less/client_action.less
@@ -6,9 +6,277 @@
 .o_mail_chat {
     .o-position-absolute(0, 0, 0, 0);
     height: 100%;
+    overflow: hidden;
 
     @media (max-width: @screen-xs-max) {
         height: auto;
+
+        .o_mail_chat_inbox_starred_button {
+            position: absolute;
+            width: 100%;
+            top: 40px;
+            padding-left: 15px;
+            padding-right: 15px;
+            padding-top: 15px;
+            padding-bottom: 10px;
+            text-align: center;
+            background: #ffffff;
+
+            .o_channel_inbox_item {
+                width: 50%;
+                border: 1px solid @odoo-brand-optional;
+
+                &:first-child {
+                    border-radius: 4px 0px 0px 4px;
+                }
+                &:last-child {
+                    border-radius: 0px 4px 4px 0px;
+                }
+            }
+        }
+
+        .o_mail_chat_content {
+            padding-top: 80px;
+            padding-bottom: 55px;
+
+            .o_mail_no_content {
+                padding-top: 30px;
+                display: block;
+                text-align: center;
+                margin: auto 0px;
+                position: absolute;
+                top: 30%;
+                width: 100%;
+            }
+        }
+
+        .o_mail_chat_mobile_tabs {
+            display: block !important;
+        }
+
+        .o_mail_chat_tab_pane {
+            display: none;
+            position: relative;
+            height: 100%;
+            padding-top: 50px;
+            padding-bottom: 55px;
+            overflow-x: scroll;
+            display: block;
+            background: #ffffff;
+
+            .o_mail_mobile_add_channel {
+                width: auto;
+                padding: 5px 0px; // larger padding-left than titles
+                position: relative;
+                margin: 10px;
+                display: none;
+                border: 1px solid #afafaf;
+                border-radius: 4px;
+
+                > input {
+                    width: 100%;
+                    padding: 5px 8px;
+                    padding-left: 20px;
+                    border: none;
+                }
+                > span {
+                    position: absolute;
+                    top: 10px;
+                    left: 10px;
+                }
+            }
+
+            .o_mail_tab_pane_item {
+                padding: 15px;
+                border-bottom: 1px solid #ebebeb;
+                overflow: hidden;
+                max-height: 100px;
+                position: relative;
+
+                &:last-child {
+                    border: none;
+                }
+
+                .item_avatar_status {
+                    display: inline-block;
+                    position: absolute;
+                    top: 15px;
+                    left: 10px;
+                    width: 55px;
+                    vertical-align: top;
+
+                    img {
+                        border-radius: 4px;
+                        max-width: 55px;
+                    }
+
+                    .o_mail_user_status {
+                        position: absolute;
+                        bottom: 5px;
+                        right: -8px;
+                        font-size: 13px;
+                        color: #cc0000;
+                        border-radius: 30px;
+                        background: #fff;
+                        padding: 2px;
+
+                        &.o_user_online {
+                            color: #21b799;
+                        }
+                    }
+                }
+
+                .chat_user_detail {
+                    display: inline-block;
+                    width: 100%;
+                    vertical-align: middle;
+                    padding-top: 5px;
+                    padding-left: 65px;
+
+                    h2 {
+                        font-size: 17px;
+                        display: block;
+                        font-weight: 500;
+                        margin: 0px;
+                        padding: 0px;
+                        color: #414141;
+
+                        small {
+                            float: right;
+                        }
+
+                        &.unread {
+                            font-weight: 700;
+                        }
+                    }
+
+                    p {
+                        display: inline-block;
+                        color: #b3b3b3;
+                        max-height: 27px;
+                        margin-top: 10px;
+                        overflow: hidden;
+                        line-height: 15px;
+
+                        &.unread{
+                            font-weight: 700;
+                            color: #8f8f8f;
+                        }
+                    }
+                }
+            }
+        }
+
+        .o_mail_chat_mobile_control_panel {
+            display: block !important;
+        }
+    }
+
+    .o_mail_chat_mobile_control_panel {
+        display: none;
+        position: absolute;
+        background: #ffffff;
+        top: 0px;
+        left: 0px;
+        width: 100%;
+        padding: 5px;
+        min-height: 44px;
+        box-shadow: 0px 0px 20px #afafaf;
+        border-bottom: 1px solid #ebebeb;
+        height: auto;
+        z-index: 1;
+
+        .o_mail_channel_title {
+            padding: 5px 10px 5px 0px;
+            color: #8f8f8f;
+            font-size: 14px;
+        }
+
+        .o_searchview {
+            color: #414141;
+            background: none;
+            border-color: transparent;
+            padding: 5px 5px 0px 5px;
+
+            .o_searchview_input {
+                width: 250px;
+                font-size: 15px;
+            }
+        }
+
+        .o_enable_searchview, .o_enable_searchview:focus,
+            .o_enable_searchview:hover, .o_enable_searchview:active  {
+                color: #414141;
+                background: none;
+                border-color: transparent;
+                display: inline-block;
+                width: auto;
+                position: absolute;
+                right: 5px;
+                top: 5px;
+
+                &::before {
+                    font-size: 15px;
+                }
+        }
+        .o_searchview_more {
+            display: none;
+        }
+    }
+
+    .o_mail_chat_mobile_tabs {
+        display: none;
+        background: #fff;
+        box-shadow: 0px 0px 20px #afafaf;
+        position: absolute;
+        bottom: 0px;
+        left: 0px;
+        width: 100%;
+
+        .o_mail_chat_mobile_tab {
+            display: inline-block;
+            width: 20%;
+            height: 100%;
+            min-height: 100%;
+            padding: 8px 4px;
+            text-align: center;
+            float: left;
+
+            &:first-child:nth-last-child(4),
+            &:first-child:nth-last-child(4) ~ .o_mail_chat_mobile_tab {
+               width: 25%;
+            }
+
+            &:first-child:nth-last-child(5),
+            &:first-child:nth-last-child(5) ~ .o_mail_chat_mobile_tab {
+               width: 20%;
+            }
+
+            &:not(:last-child) {
+               border-right: 1px solid #d7d7d7;
+            }
+
+            span {
+               display: block;
+               &.fa {
+                   font-size: 16px;
+               }
+
+               &.o_tab_title{
+                   font-size: 8px;
+                   padding-top: 8px;
+               }
+            }
+            &.active {
+               span {
+                   color: @odoo-brand-optional;
+               }
+            }
+        }
+    }
+
+    .o_mail_chat_tab_pane {
+        display: none;
     }
 
     .o_mail_annoying_notification_bar {
@@ -132,6 +400,8 @@
 
         @media (max-width: @screen-xs-max) {
             margin-left: 0;
+            display: block;
+            overflow-x: scroll;
         }
 
         @media (min-width: @screen-lg-min) {
@@ -267,7 +537,6 @@
 .o_mail_user_status {
     font-size: 1em;
     position: relative;
-
     &.o_user_online {
         color: @brand-success;
     }
diff --git a/addons/mail/static/src/less/composer.less b/addons/mail/static/src/less/composer.less
index e32c1167ac2..8144fb860ee 100644
--- a/addons/mail/static/src/less/composer.less
+++ b/addons/mail/static/src/less/composer.less
@@ -171,19 +171,21 @@
         .o_composer_input {
             .o-flex-display();
             .o-flex-flow(row, nowrap);
-            padding: @o-mail-chatter-gap;
 
             textarea.o_composer_text_field {
                 .o-flex(1, 1, auto);
-                padding-top: @o-mail-chatter-gap*0.5;
             }
 
             .o_chatter_composer_tools {
                 .o-flex(0, 0, auto);
             }
+            @media (max-width: @screen-xs-max) {
+                .o_composer_button_send {
+                    display: inline-block;
+                }
+            }
         }
-
-        .o_composer_button_send, .o_chatter_avatar, .o_composer_button_add_attachment, .o_composer_attachments_list {
+        .o_composer_button_send, .o_chatter_avatar {
             display: none;
         }
     }
@@ -197,8 +199,8 @@
 // Emoji
 .o_mail_emoji {
     display: inline-block;
-    width: 24px;
-    height: 24px;
+    height: 20px;
+    width: 20px;
 
     > img {
         width: 100%;
diff --git a/addons/mail/static/src/less/extended_chat_window.less b/addons/mail/static/src/less/extended_chat_window.less
index 028befebdf9..618211b7718 100644
--- a/addons/mail/static/src/less/extended_chat_window.less
+++ b/addons/mail/static/src/less/extended_chat_window.less
@@ -24,4 +24,55 @@
             display: none;
         }
     }
+
+    .o_chat_composer {
+        background: #fff;
+        border-top: 1px solid #d9d9d9;
+        position: relative;
+        .o_composer {
+            .o_composer_input {
+                display: inline-block;
+                float: left;
+                width: 70%;
+                textarea {
+                    display: block;
+                    padding: 10px;
+                    font-size: 13px;
+
+                    @media (max-width: @screen-xs-max) {
+                        padding: 15px 10px;
+                    }
+                }
+            }
+
+            .o_chatter_composer_tools {
+                position: absolute;
+                right: 0px;
+                top: 0px;
+
+                button {
+                    padding: 10px;
+                    @media (max-width: @screen-xs-max) {
+                        padding: 13px;
+                    }
+                    &.btn-icon{
+                        font-size: 1.3em;
+                    }
+                }
+            }
+        }
+        .o_composer_tabs_toggle_button {
+            display: none;
+        }
+        .o_composer_attachments_list {
+            margin: 0px;
+        }
+        .o_composer_attachments_list, .o_composer_buttons {
+            .o_composer_button_emoji, .o_composer_button_add_attachment {
+                &:hover, &:focus {
+                    background-color: #FFFFFF !important;
+                }
+            }
+        }
+    }
 }
diff --git a/addons/mail/static/src/less/systray.less b/addons/mail/static/src/less/systray.less
index 1ecb50989aa..584bda51023 100644
--- a/addons/mail/static/src/less/systray.less
+++ b/addons/mail/static/src/less/systray.less
@@ -22,11 +22,12 @@
     .o_notification_counter {
         background: @odoo-brand-optional;
         color: white;
-        padding: 0em 0.3em;
+        padding: 0em 0.5em;
         font-size: 0.7em;
-        top: 19%;
+        top: 0px;
+        right: 0px;
         position: absolute;
-        margin: 0px 0px 0px 6px;
+        margin: 0px;
     }
     .o_mail_navbar_dropdown {
         width: 350px;
@@ -45,7 +46,9 @@
             .o-flex(0, 0, auto);
             justify-content: space-between;
             border-bottom: 1px solid lightgray;
-
+            @media (max-width: @screen-xs-max) {
+                padding: 5px;
+            }
             .o_filter_button, .o_new_message {
                 .btn-link;
                 padding: 5px;
@@ -80,6 +83,10 @@
                 cursor: pointer;
                 font-size: 12px;
                 overflow: hidden;
+                @media (max-width: @screen-xs-max) {
+                    padding: 10px;
+                    height: 85px;
+                }
                 &~.o_mail_channel_preview {
                     border-top: 1px solid lightgray;
                 }
@@ -93,6 +100,12 @@
                 .o_channel_image {
                     .o-flex(0, 0, 36px);
                     max-height: 36px;
+                    @media (max-width: @screen-xs-max) {
+                        .o-flex(0, 0, 50px);
+                        border-radius: 3px;
+                        margin-right: 10px;
+                        max-height: 50px;
+                    }
                 }
                 .o_channel_info {
                     .o-flex(1, 1, 100%);
@@ -105,6 +118,11 @@
                             .o-flex(1, 1, auto);
                             .o-text-overflow();
                             color: @odoo-main-text-color;
+                            @media (max-width: @screen-xs-max) {
+                                font-size: 1.4em;
+                                color: #000;
+                                font-weight: 300;
+                            }
                         }
                         .o_last_message_date {
                             .o-flex(0, 0, auto);
@@ -133,9 +151,86 @@
             opacity: 0.5;
             padding: 3px;
         }
+
+        &.o_mail_navbar_mobile {
+            position: relative;
+
+            .o_mail_navbar_mobile_header {
+                padding: 5px 5px 5px 0px;
+                min-height: 44px;
+                border-bottom: 1px solid #ccc;
+                background: #ffffff;
+            }
+
+            .o_mail_navbar_dropdown_channels {
+                padding-bottom: 55px;
+            }
+
+            .o_mail_navbar_mobile_tabs {
+                background: #fff;
+                box-shadow: 0px 0px 20px #afafaf;
+                position: fixed;
+                bottom: 0px;
+                left: 0px;
+                width: 100%;
+
+                .o_mail_navbar_mobile_tab {
+                    display: inline-block;
+                    width: 20%;
+                    height: 100%;
+                    min-height: 100%;
+                    padding: 8px 4px;
+                    text-align: center;
+                    float: left;
+                    font-size: 1.2em;
+                    color: #666666;
+
+                    &:first-child:nth-last-child(3),
+                    &:first-child:nth-last-child(3) ~ .o_mail_navbar_mobile_tab {
+                        width: 33.33%;
+                    }
+
+                    &:first-child:nth-last-child(4),
+                    &:first-child:nth-last-child(4) ~ .o_mail_navbar_mobile_tab {
+                        width: 25%;
+                    }
+
+                    &:first-child:nth-last-child(5),
+                    &:first-child:nth-last-child(5) ~ .o_mail_navbar_mobile_tab {
+                        width: 20%;
+                    }
+
+                    &:not(:last-child) {
+                        border-right: 1px solid #d7d7d7;
+                    }
+
+                    span {
+                        display: block;
+                        &.fa {
+                           font-size: 16px;
+                        }
+
+                        &.o_tab_title{
+                           font-size: 11px;
+                           padding-top: 8px;
+                        }
+                    }
+                    &.o_selected {
+                        span {
+                           color: @odoo-brand-optional;
+                        }
+                    }
+                }
+            }
+        }
     }
 }
 
 .o_no_chat_window .o_mail_navbar_dropdown .o_new_message {
     display: none;  // hide 'new message' button if chat windows are disabled
 }
+
+// Fix for enterprise nav bar
+.o_main_navbar .o_menu_systray .o_notification_counter {
+    top: 5px;
+}
diff --git a/addons/mail/static/src/less/thread.less b/addons/mail/static/src/less/thread.less
index 16e58a8e285..859e9f32fee 100644
--- a/addons/mail/static/src/less/thread.less
+++ b/addons/mail/static/src/less/thread.less
@@ -96,6 +96,69 @@
             cursor: pointer;
         }
 
+        .o_message_attachments {
+            display: block;
+            position: relative;
+            padding: 0px;
+            margin: 0px;
+
+            .o_attachment {
+                width: initial;
+                height: initial;
+
+                .o_image {
+                    position: initial;
+                    top: initial;
+                    left: initial;
+                    bottom: initial;
+                    right: initial;
+                }
+            }
+
+            .o_message_attachment {
+                display: inline-block;
+                padding: 5px;
+                border-radius: 4px;
+                margin: 5px 5px 5px 5px;
+                position: relative;
+                background-color: #cccccc;
+
+                .download_icon {
+                    position: absolute;
+                    top: 0;
+                    left: 0;
+                    width: 100%;
+                    height: 100%;
+                    span {
+                        background: rgba(0, 0, 0, 0.5);
+                        position: absolute;
+                        top: 37%;
+                        left: 37%;
+                        padding: 5px;
+                        border-radius: 30px;
+                        color: #fff;
+                    }
+                }
+
+                a.o_image {
+                    width: 80px;
+                    height: 60px;
+                }
+
+                img {
+                    height: 60px;
+                    width: 80px;
+                    opacity: 0.5;
+
+                    &.o_image_view {
+                        cursor: pointer;
+                        background-color: #000;
+                        object-fit: none;
+                    }
+                }
+            }
+        }
+
         .o_thread_message_core {
             .o-flex(1, 1, auto);
             min-width: 0;
diff --git a/addons/mail/static/src/xml/chat_window.xml b/addons/mail/static/src/xml/chat_window.xml
index a9117c76bd6..b8e22e99249 100644
--- a/addons/mail/static/src/xml/chat_window.xml
+++ b/addons/mail/static/src/xml/chat_window.xml
@@ -41,12 +41,15 @@
     </t>
 
     <t t-name="mail.ChatWindowHeaderContent">
+        <span t-if="isMobile">
+            <a href="#" class="o_chat_window_close fa fa-1x fa-arrow-left mr4"/>
+        </span>
         <span class="o_chat_title">
             <t t-if="status" t-call="mail.chat.UserStatus"/>
             <t t-esc="title"/>
             <span t-if="unread_counter"> (<t t-esc="unread_counter"/>)</span>
         </span>
-        <span class="o_chat_window_buttons">
+        <span t-if="!isMobile" class="o_chat_window_buttons">
             <a href="#" class="o_chat_window_close fa fa-close"/>
         </span>
     </t>
diff --git a/addons/mail/static/src/xml/client_action.xml b/addons/mail/static/src/xml/client_action.xml
index b4539dd7bb7..7435914f139 100644
--- a/addons/mail/static/src/xml/client_action.xml
+++ b/addons/mail/static/src/xml/client_action.xml
@@ -6,7 +6,7 @@
         <div class="o_mail_chat">
             <div class="o_mail_chat_sidebar"/>
             <div class="o_mail_chat_content">
-                <t t-if="widget.notification_bar">
+                <t t-if="widget.notification_bar &amp;&amp; !widget.isMobile">
                     <div class="o_mail_annoying_notification_bar">
                         <span class="o_mail_request_permission">Odoo needs your permission to <a href="#"> enable desktop notifications</a>.</span>
                         <span class="fa fa-close"></span>
@@ -129,13 +129,14 @@
 
     <!-- Buttons of the Control Panel -->
     <t t-name="mail.chat.ControlButtons">
-        <div>
-            <button type="button" class="btn btn-primary btn-sm o_mail_toggle_channels visible-xs-inline" title="Toggle Channels">Channels</button>
+        <div class="o_mail_chat_buttons">
             <button type="button" class="btn btn-primary btn-sm o_mail_chat_button_invite" title="Invite people">Invite</button>
-            <button type="button" class="btn btn-default btn-sm o_mail_chat_button_mark_read hidden-xs" title="Mark all as read">Mark all read</button>
-            <button type="button" class="btn btn-primary btn-sm o_mail_chat_button_unstar_all" title="Unstar all messages">Unstar all</button>
+            <button type="button" class="btn btn-default btn-sm o_mail_chat_button_mark_read" title="Mark all as read">Mark all read</button>
+            <button type="button" class="btn btn-default btn-sm o_mail_chat_button_unstar_all" title="Unstar all messages">Unstar all</button>
             <button type="button" class="btn btn-default btn-sm o_mail_chat_button_unsubscribe" title="Unsubscribe from channel">Unsubscribe</button>
-            <button type="button" class="btn btn-default btn-sm o_mail_chat_button_settings" title="Open channel settings">Settings</button>
+            <button type="button" class="btn btn-default btn-sm o_mail_chat_button_dm o_hidden visible-xs" title="New Message">New Message</button>
+            <button t-if="!disable_add_channel" type="button" class="btn btn-default btn-sm o_mail_chat_button_public o_mail_chat_button_private o_hidden visible-xs" title="New Channel">New Channel</button>
+            <button t-if="debug" type="button" class="btn btn-default btn-sm o_mail_chat_button_settings" title="Open channel settings">Settings</button>
         </div>
     </t>
 
@@ -143,4 +144,87 @@
     <div t-name="mail.PartnerInviteDialog">
         <input type="text" class="o_input o_mail_chat_partner_invite_input" id="mail_search_partners"/>
     </div>
+
+    <t t-name="mail.chat.MobileInboxStarredButtons">
+       <div class="o_mail_chat_inbox_starred_button">
+           <button type="button" class="btn btn-primary btn-sm visible-xs-inline o_channel_inbox_item" title="Inbox" data-type="channel_inbox">Inbox</button><button type="button" class="btn btn-default btn-sm visible-xs-inline o_channel_inbox_item" title="Starred" data-type="channel_starred">Starred</button>
+       </div>
+    </t>
+
+    <t t-name="mail.chat.MobileControlPanel">
+        <div class="o_mail_chat_mobile_control_panel"/>
+    </t>
+
+    <t t-name="mail.chat.MobileTabs">
+        <div class="o_mail_chat_mobile_tabs">
+            <div class="o_mail_chat_mobile_tab" data-channel-id="channel_inbox" data-type="channel_inbox">
+                <span class="fa fa-envelope"/>
+                <span class="o_tab_title">Inbox</span>
+            </div>
+            <div class="o_mail_chat_mobile_tab" data-type="dm">
+                <span class="fa fa-comments"/>
+                <span class="o_tab_title">Chat</span>
+            </div>
+            <div class="o_mail_chat_mobile_tab" data-type="public">
+                <span class="fa fa-users"/>
+                <span class="o_tab_title">Channels</span>
+            </div>
+            <div class="o_mail_chat_mobile_tab" data-type="private">
+                <span class="fa fa-lock"/>
+                <span class="o_tab_title">Private&amp;nbsp;Channels</span>
+            </div>
+        </div>
+    </t>
+
+    <t t-name="mail.chat.MobileTabPanes">
+        <t t-foreach="channels" t-as="item">
+            <div class="o_mail_chat_tab_pane" t-att-data-type="item.type">
+                <div t-if="!disable_add_channel" class="o_mail_add_channel o_mail_mobile_add_channel" t-att-data-type="type">
+                    <span t-if="type == 'private' || type == 'public'">#</span>
+                    <t t-set="input_placeholder" t-if="type == 'private' || 'public'">Add a channel</t>
+                    <t t-set="input_placeholder" t-if="type == 'dm'">Open chat</t>
+                    <input type="text" t-attf-placeholder="#{input_placeholder}"/>
+                </div>
+                <t t-foreach="item.channels" t-as="channel">
+                    <t t-call="mail.chat.MobileTabPaneItems">
+                        <t t-set="type" t-value="item.type"/>
+                    </t>
+                </t>
+            </div>
+        </t>
+    </t>
+
+    <t t-name="mail.chat.MobileTabPaneItems">
+        <div class="o_mail_tab_pane_item" t-att-data-channel-id="channel.id">
+            <div class="item_avatar_status">
+                <img t-if="type == 'dm'" t-att-src="'/web/image/res.partner/'+ channel.direct_partner_id+'/image_small'"/>
+                <img t-if="type != 'dm'" t-att-src="'/web/image/mail.channel/'+ channel.id+'/image_small'"/>
+                <i t-if="channel.status == 'online'" class="o_mail_user_status o_user_online fa fa-circle" title="Online"/>
+                <i t-if="channel.status == 'away'" class="o_mail_user_status o_user_idle fa fa-circle" title="Idle"/>
+                <i t-if="channel.status == 'offline'" class="o_mail_user_status fa fa-circle" title="Offline"/>
+            </div>
+            <t t-set="is_author" t-value="channel.last_message &amp;&amp; channel.last_message.author_id[0] == partner_id"/>
+            <t t-set="is_unread" t-value="channel.last_message &amp;&amp; channel.last_seen_message_id &lt; channel.last_message.id &amp;&amp; !is_author"/>
+            <div class="chat_user_detail">
+                <h2 t-attf-class="#{is_unread ? 'unread' : ''}"><t t-esc="channel.name"/><small class="o_message_timestamp" t-attf-title="#{channel.last_message ? channel.last_message.date : ''}"><t t-if="channel.last_message" t-esc="moment(channel.last_message.date).fromNow()"/></small></h2>
+                <p t-attf-class="#{is_unread ? 'unread' : ''}">
+                    <t t-if="channel.last_message">
+                        <span t-if="is_author" class="fa fa-mail-reply"/>
+                        <t t-if="channel.last_message" t-raw="get_message_body_preview(channel.last_message.body)"/>
+                        <t t-if="channel.last_message.body == ''">
+                            <t t-if="channel.last_message.attachment_ids.length != 0">
+                                <t t-esc="channel.last_message.attachment_ids.length"/> attachment(s)
+                            </t>
+                            <t t-if="channel.last_message.tracking_value_ids and channel.last_message.tracking_value_ids.length &gt; 0">
+                                <t t-if="channel.last_message.subtype_description">
+                                    <strong><t t-esc="channel.last_message.record_name"/></strong>
+                                    : <t t-esc="channel.last_message.subtype_description"/>
+                                </t>
+                            </t>
+                        </t>
+                    </t>
+                </p>
+            </div>
+        </div>
+    </t>
 </templates>
diff --git a/addons/mail/static/src/xml/composer.xml b/addons/mail/static/src/xml/composer.xml
index 68c2730707e..9305728ebfe 100644
--- a/addons/mail/static/src/xml/composer.xml
+++ b/addons/mail/static/src/xml/composer.xml
@@ -13,6 +13,7 @@
                     <div class="o_chatter_composer_tools">
                         <button tabindex="4" class="btn btn-sm btn-icon fa fa-smile-o o_composer_button_emoji" type="button" data-toggle="popover"/>
                         <button tabindex="5" class="btn btn-sm btn-icon fa fa-paperclip o_composer_button_add_attachment" type="button"/>
+                        <button t-if="widget.options.isMobile" tabindex="3" class="btn btn-sm btn-icon fa fa-paper-plane-o o_composer_button_send o_composer_mobile_button" type="button"/>
                     </div>
                 </div>
              </div>
diff --git a/addons/mail/static/src/xml/extended_chat_window.xml b/addons/mail/static/src/xml/extended_chat_window.xml
index 5548688d462..865bb7c2968 100644
--- a/addons/mail/static/src/xml/extended_chat_window.xml
+++ b/addons/mail/static/src/xml/extended_chat_window.xml
@@ -12,7 +12,7 @@
 
     <t t-extend="mail.ChatWindowHeaderContent">
         <t t-jquery=".o_chat_window_close" t-operation="before">
-            <a href="#" class="o_chat_window_expand fa fa-expand" title="
+            <a t-if="!isMobile" href="#" class="o_chat_window_expand fa fa-expand" title="
             Open in Discuss"/>
         </t>
     </t>
diff --git a/addons/mail/static/src/xml/systray.xml b/addons/mail/static/src/xml/systray.xml
index 8e7e9b161d4..ebc65ecfe2f 100644
--- a/addons/mail/static/src/xml/systray.xml
+++ b/addons/mail/static/src/xml/systray.xml
@@ -6,8 +6,13 @@
             <a class="dropdown-toggle" data-toggle="dropdown" aria-expanded="false" title="Conversations" href="#">
                 <i class="fa fa-comments"/> <span class="o_notification_counter badge"/>
             </a>
-            <ul class="o_mail_navbar_dropdown dropdown-menu" role="menu">
-                <li class="o_mail_navbar_dropdown_top">
+            <ul t-att-class="'o_mail_navbar_dropdown dropdown-menu ' + (widget.isMobile ? 'o_mail_navbar_mobile' : '')" role="menu">
+                <li t-if="widget.isMobile">
+                    <div class="o_mail_navbar_mobile_header">
+                        <button type="button" class="btn btn-default btn-sm o_new_message"> New message </button>
+                    </div>
+                </li>
+                <li t-if="!widget.isMobile" class="o_mail_navbar_dropdown_top">
                     <div>
                         <button type="button" class="btn btn-sm o_filter_button o_selected"> All </button>
                         <button type="button" class="btn btn-sm o_filter_button" data-filter='chat'> Chat </button>
@@ -16,6 +21,22 @@
                     <button type="button" class="btn btn-sm o_new_message"> New message </button>
                 </li>
                 <li class="o_mail_navbar_dropdown_channels"/>
+                <li t-if="widget.isMobile">
+                    <div class="o_mail_navbar_mobile_tabs">
+                        <div class="o_mail_navbar_mobile_tab o_filter_button o_selected">
+                            <span class="fa fa-envelope"/>
+                            <span class="o_tab_title">All</span>
+                        </div>
+                        <div class="o_mail_navbar_mobile_tab o_filter_button" data-filter='chat'>
+                            <span class="fa fa-comments"/>
+                            <span class="o_tab_title">Chat</span>
+                        </div>
+                        <div class="o_mail_navbar_mobile_tab o_filter_button" data-filter='channels'>
+                            <span class="fa fa-users"/>
+                            <span class="o_tab_title">Channels</span>
+                        </div>
+                    </div>
+                </li>
             </ul>
         </li>
     </t>
@@ -70,8 +91,8 @@
                         <span t-if="!activity.overdue_count" class="o_no_activity mr16">0 Late </span>
                         <button t-if="activity.today_count" type="button" class="btn btn-link o_activity_filter_button mr16" t-att-data-res_model="activity.model" t-att-data-model_name="activity.name" data-filter='today'> <t t-esc="activity.today_count"/> Today </button>
                         <span t-if="!activity.today_count" class="o_no_activity mr16">0 Today </span>
-                        <button t-if="activity.planned_count" type="button" class="btn btn-link o_activity_filter_button pull-right mr16" t-att-data-res_model="activity.model" t-att-data-model_name="activity.name" data-filter='upcoming_all'> <t t-esc="activity.planned_count"/> Future </button>
-                        <span t-if="!activity.planned_count" class="o_no_activity pull-right mr16">0 Future</span>
+                        <button t-if="activity.planned_count" type="button" class="btn btn-link o_activity_filter_button pull-right" t-att-data-res_model="activity.model" t-att-data-model_name="activity.name" data-filter='upcoming_all'> <t t-esc="activity.planned_count"/> Future </button>
+                        <span t-if="!activity.planned_count" class="o_no_activity pull-right">0 Future</span>
                     </div>
                 </div>
             </div>
diff --git a/addons/mail/static/src/xml/thread.xml b/addons/mail/static/src/xml/thread.xml
index 8237658e99e..054576ed923 100644
--- a/addons/mail/static/src/xml/thread.xml
+++ b/addons/mail/static/src/xml/thread.xml
@@ -3,10 +3,10 @@
 
     <t t-name="mail.ChatThread">
         <t t-if="messages.length">
-            <t t-if="options.display_load_more &amp;&amp; options.display_order == ORDER.ASC"
+            <t t-if="options.display_load_more and options.display_order == ORDER.ASC"
                t-call="mail.ChatThread.LoadMore"/>
             <t t-call="mail.ChatThread.Content"/>
-            <t t-if="options.display_load_more &amp;&amp; options.display_order == ORDER.DESC"
+            <t t-if="options.display_load_more and options.display_order == ORDER.DESC"
                t-call="mail.ChatThread.LoadMore"/>
         </t>
         <t t-if="options.display_empty_channel">
@@ -133,22 +133,22 @@
     <t t-name="mail.ChatThread.Message">
         <div t-att-class="'o_thread_message' + (message.expanded ? ' o_message_expanded '  : ' ') + (message.is_selected ? 'o_thread_selected_message' : '')" t-att-data-message-id="message.id">
             <div t-if="options.display_avatar" class="o_thread_message_sidebar">
-                <t t-if="!message.mailto &amp;&amp; message.author_id[0]">
-                    <img t-if="message.avatar_src &amp;&amp; message.display_author"
+                <t t-if="!message.mailto and message.author_id[0]">
+                    <img t-if="message.avatar_src and message.display_author"
                         t-att-src="message.avatar_src"
                         data-oe-model="res.partner"
                         t-att-data-oe-id="message.author_redirect ? message.author_id[0] : ''"
                         t-attf-class="o_thread_message_avatar img-circle #{message.author_redirect ? 'o_mail_redirect' : ''}"/>
                 </t>
                 <t t-if="message.mailto || !message.author_id[0]">
-                    <img t-if="message.avatar_src &amp;&amp; message.display_author"
+                    <img t-if="message.avatar_src and message.display_author"
                         t-att-src="message.avatar_src"
                         class="o_thread_message_avatar img-circle"/>
                 </t>
                 <span t-if="!message.display_author" t-att-title="message.date" class="o_thread_message_side_date">
                     <t t-esc="message.date.format('hh:mm')"/>
                 </span>
-                <i t-if="!message.display_author &amp;&amp; options.display_stars &amp;&amp; message.message_type != 'notification'"
+                <i t-if="!message.display_author and options.display_stars and message.message_type != 'notification'"
                     t-att-class="'fa o_thread_message_star ' + (message.is_starred ? 'fa-star' : 'fa-star-o')"
                     t-att-data-message-id="message.id" title="Mark as Todo"/>
             </div>
@@ -163,23 +163,23 @@
                             <t t-esc="message.mailto"/>
                         </a>
                     </strong>
-                    <strong t-if="!message.mailto &amp;&amp; message.author_id[0]"
+                    <strong t-if="!message.mailto and message.author_id[0]"
                             data-oe-model="res.partner" t-att-data-oe-id="message.author_redirect ? message.author_id[0] : ''"
-                            t-attf-class="#{message.author_redirect ? 'o_mail_redirect' : ''}">
+                            t-attf-class="o_thread_author #{message.author_redirect ? 'o_mail_redirect' : ''}">
                         <t t-esc="message.displayed_author"/>
                     </strong>
-                    <strong t-if="!message.mailto &amp;&amp; !message.author_id[0]">
+                    <strong t-if="!message.mailto and !message.author_id[0]" class="o_thread_author">
                         <t t-esc="message.displayed_author"/>
                     </strong>
 
                     - <small class="o_mail_timestamp" t-att-title="message.date"><t t-esc="message.hour"/></small>
-                    <t t-if="message.model &amp;&amp; (message.model != 'mail.channel') &amp;&amp; options.display_document_link">
-                        on <a t-att-href="message.url" t-att-data-oe-model="message.model" t-att-data-oe-id="message.res_id"><t t-esc="message.record_name"/></a>
+                    <t t-if="message.model and (message.model != 'mail.channel') and options.display_document_link">
+                        <a t-att-href="message.url" t-att-data-oe-model="message.model" t-att-data-oe-id="message.res_id" class="o_document_link">on <t t-esc="message.record_name"/></a>
                     </t>
-                    <t t-if="message.origin_id &amp;&amp; (message.origin_id !== options.channel_id)">
+                    <t t-if="message.origin_id and (message.origin_id !== options.channel_id)">
                         (from <a t-att-data-oe-id="message.origin_id" href="#">#<t t-esc="message.origin_name"/></a>)
                     </t>
-                    <span t-if="options.display_email_icon &amp;&amp; message.customer_email_data &amp;&amp; message.customer_email_data.length" class="o_thread_tooltip_container">
+                    <span t-if="options.display_email_icon and message.customer_email_data and message.customer_email_data.length" class="o_thread_tooltip_container">
                         <i t-att-class="'o_thread_tooltip o_thread_message_email o_thread_message_email_' + message.customer_email_status + ' fa fa-envelope-o'"/>
                         <span class="o_thread_tooltip_content">
                             <t t-foreach="message.customer_email_data" t-as="customer">
@@ -206,19 +206,21 @@
                            t-att-data-message-id="message.id" title="Mark as Read"/>
                     </span>
                 </p>
-                <t t-if="message.tracking_value_ids &amp;&amp; message.tracking_value_ids.length &gt; 0">
-                    <t t-if="message.subtype_description">
-                        <p t-esc="message.subtype_description"/>
+                <div class="o_thread_message_content">
+                    <t t-if="message.tracking_value_ids and message.tracking_value_ids.length &gt; 0">
+                        <t t-if="message.subtype_description">
+                            <p><t t-esc="message.subtype_description"/></p>
+                        </t>
+                        <t t-call="mail.ChatThread.MessageTracking"/>
                     </t>
-                    <t t-call="mail.ChatThread.MessageTracking"/>
-                </t>
-                <p t-if="options.display_subject &amp;&amp; message.display_subject" class="o_mail_subject">Subject: <t t-esc="message.subject"/></p>
-                <t t-if="!(message.tracking_value_ids &amp;&amp; message.tracking_value_ids.length &gt; 0)">
-                    <t t-raw="message.body"/>
-                </t>
-                <t t-foreach="message.attachment_ids" t-as="attachment">
-                    <t t-call="mail.Attachment"/>
-                </t>
+                    <p t-if="options.display_subject and message.display_subject" class="o_mail_subject">Subject: <t t-esc="message.subject"/></p>
+                    <t t-if="!(message.tracking_value_ids and message.tracking_value_ids.length &gt; 0)">
+                        <t t-raw="message.body"/>
+                    </t>
+                     <t t-foreach="message.attachment_ids" t-as="attachment">
+                         <t t-call="mail.Attachment"/>
+                     </t>
+                </div>
             </div>
         </div>
         <t t-if="options.messages_separator_position == message.id">
@@ -329,5 +331,4 @@
             <button class="btn btn-sm btn-link">-------- Show older messages --------</button>
         </div>
     </t>
-
 </templates>
diff --git a/addons/mail/static/tests/client_action_tests.js b/addons/mail/static/tests/client_action_tests.js
new file mode 100644
index 00000000000..a5f71c85b03
--- /dev/null
+++ b/addons/mail/static/tests/client_action_tests.js
@@ -0,0 +1,89 @@
+odoo.define('mail.client_action_test', function (require) {
+"use strict";
+
+var ActionManager = require('web.ActionManager');
+var core = require('web.core');
+var testUtils = require('web.test_utils');
+var Widget = require('web.Widget');
+
+var ChatAction = require("mail.chat_client_action");
+
+QUnit.module('mail', {}, function () {
+
+QUnit.module('ChatAction', {
+    beforeEach: function () {
+        this.data = {
+            "mail.message": {
+                fields: {
+                    id: {type: 'integer', string: 'ID'}
+                }
+            }
+        };
+    }
+});
+
+//--------------------------------------------------------------------------
+// Mobile Test case
+//--------------------------------------------------------------------------
+
+QUnit.test('mobile basic rendering', function (assert) {
+    assert.expect(11);
+
+    function createParent (params) {
+        var actionManager = new ActionManager();
+        testUtils.addMockEnvironment(actionManager, params);
+        return actionManager;
+    }
+
+    var action = {
+        id: 1,
+        context: {'active_channel_id': 'channel_inbox', 'active_ids': ['channel_inbox']},
+        params: {'default_active_id': 'channel_inbox'}
+    };
+
+    var parent = createParent({
+        data: {},
+    });
+
+    testUtils.addMockEnvironment(parent, {
+        data: this.data,
+        config: {
+            isMobile: true
+        },
+        archs: {
+            'mail.message,false,search': '<search/>',
+        }
+    });
+
+    var chatAction = new ChatAction(parent, action, {});
+    chatAction.set_cp_bus(new Widget());
+
+    chatAction.appendTo($('#qunit-fixture'));
+
+    // test for basic view rendering for mobile
+    assert.equal(chatAction.$(".o_mail_chat_mobile_control_panel").length, 1, "Mobile control panel created");
+    assert.equal(chatAction.$(".o_mail_chat_mobile_tab").length, 4, "Four mobile tabs created");
+    assert.equal(chatAction.$('.o_mail_chat_content').length, 1, "One default chat content pane created");
+    assert.equal(chatAction.$(".o_mail_chat_tab_pane").length, 3, "Three mobile tab panes created");
+
+    // Inbox
+    assert.equal(chatAction.activeMobileTab, "channel_inbox", "'channel_inbox' is default active tab");
+    assert.ok(chatAction.$(".o_channel_inbox_item:nth(0)").hasClass("btn-primary"), "Showing 'Inbox'");
+
+    // Starred
+    chatAction.mailMobileInboxButtons.find(".o_channel_inbox_item[data-type='channel_starred']").click();
+    assert.ok(chatAction.$(".o_channel_inbox_item:nth(1)").hasClass("btn-primary"), "Clicked on 'Starred'");
+
+    assert.ok(chatAction.$(".o_mail_chat_content").is(":visible"), "Default main content pane visible");
+
+    chatAction.$(".o_mail_chat_mobile_tab[data-type='dm']").click();
+    assert.equal(chatAction.activeMobileTab, "dm", "After click on 'Conversation', is now active tab");
+
+    assert.ok(!chatAction.$(".o_mail_chat_content").is(":visible"), "none", "'Main' content pane is invisible");
+    assert.ok(chatAction.$(".o_mail_chat_tab_pane:nth(0)").is(":visible"), "'Conversation' pane is visible");
+
+    chatAction.destroy();
+});
+
+});
+});
\ No newline at end of file
diff --git a/addons/mail/views/mail_templates.xml b/addons/mail/views/mail_templates.xml
index 2fe052975c3..16c033bcd3e 100644
--- a/addons/mail/views/mail_templates.xml
+++ b/addons/mail/views/mail_templates.xml
@@ -40,6 +40,7 @@
 
         <template id="qunit_suite" name="mail_tests" inherit_id="web.qunit_suite">
             <xpath expr="//t[@t-set='head']" position="inside">
+                <script type="text/javascript" src="/mail/static/tests/client_action_tests.js"></script>
                 <script type="text/javascript" src="/mail/static/tests/chatter_tests.js"></script>
                 <script type="text/javascript" src="/mail/static/tests/systray_tests.js"></script>
                 <script type="text/javascript" src="/mail/static/tests/chat_window_test.js"></script>