diff --git a/addons/mail/models/mail_channel.py b/addons/mail/models/mail_channel.py
index 2b5bfe2a2db..180a995a68f 100644
--- a/addons/mail/models/mail_channel.py
+++ b/addons/mail/models/mail_channel.py
@@ -745,20 +745,21 @@ class Channel(models.Model):
     @api.multi
     def channel_fetched(self):
         """ Broadcast the channel_fetched notification to channel members
+            :param channel_ids : list of channel id that has been fetched by current user
         """
-        self.ensure_one()
-        if not self.channel_message_ids.ids:
-            return
-        last_message_id = self.channel_message_ids.ids[0] # zero is the index of the last message
-        self.env['mail.channel.partner'].search([('channel_id', 'in', self.ids), ('partner_id', '=', self.env.user.partner_id.id)]).write({
-            'fetched_message_id': last_message_id,
-        })
-        data = {
-            'info': 'channel_fetched',
-            'last_message_id': last_message_id,
-            'partner_id': self.env.user.partner_id.id,
-        }
-        self.env['bus.bus'].sendmany([[(self._cr.dbname, 'mail.channel', self.id), data]])
+        for channel in self:
+            if not channel.channel_message_ids.ids:
+                return
+            last_message_id = channel.channel_message_ids.ids[0] # zero is the index of the last message
+            self.env['mail.channel.partner'].search([('channel_id', '=', channel.id), ('partner_id', '=', self.env.user.partner_id.id)]).write({
+                'fetched_message_id': last_message_id,
+            })
+            data = {
+                'info': 'channel_fetched',
+                'last_message_id': last_message_id,
+                'partner_id': self.env.user.partner_id.id,
+            }
+            self.env['bus.bus'].sendmany([[(self._cr.dbname, 'mail.channel', channel.id), data]])
 
     @api.multi
     def channel_invite(self, partner_ids):
diff --git a/addons/mail/static/src/js/models/threads/channel.js b/addons/mail/static/src/js/models/threads/channel.js
index 7db3474ebb2..a2316edb7be 100644
--- a/addons/mail/static/src/js/models/threads/channel.js
+++ b/addons/mail/static/src/js/models/threads/channel.js
@@ -387,23 +387,9 @@ var Channel = SearchableThread.extend(ChannelSeenMixin, ThreadTypingMixin, {
      */
     _markAsRead: function () {
         var superDef = this._super.apply(this, arguments);
-        var seenDef = this._throttleNotifySeen();
+        var seenDef = this._notifySeen();
         return $.when(superDef, seenDef);
     },
-    /**
-     * @override {mail.model.ThreadSeenMixin}
-     * @private
-     * @returns {$.Promise}
-     */
-    _notifyFetched: function () {
-        return this._rpc({
-            model: 'mail.channel',
-            method: 'channel_fetched',
-            args: [[this._id]],
-        }, {
-            shadow: true
-        });
-    },
     /**
      * @override {mail.model.ThreadTypingMixin}
      * @private
@@ -419,25 +405,6 @@ var Channel = SearchableThread.extend(ChannelSeenMixin, ThreadTypingMixin, {
             kwargs: { is_typing: params.typing },
         }, { shadow: true });
     },
-    /**
-     * @override {mail.model.ThreadSeenMixin}
-     * @private
-     * @returns {$.Promise<integer>} resolved with ID of last seen message
-     */
-    _notifySeen: function () {
-        var self = this;
-        this._cancelThrottledNotifyFetched();
-        return this._rpc({
-            model: 'mail.channel',
-            method: 'channel_seen',
-            args: [[this._id]],
-        }, {
-            shadow: true
-        }).then(function (lastSeenMessageID) {
-            self._lastSeenMessageID = lastSeenMessageID;
-            return lastSeenMessageID;
-        });
-    },
     /**
      * Prepare and send a message to the server on this channel.
      *
diff --git a/addons/mail/static/src/js/models/threads/mixins/channel_seen_mixin.js b/addons/mail/static/src/js/models/threads/mixins/channel_seen_mixin.js
index 8a59db70aa2..022994673d2 100644
--- a/addons/mail/static/src/js/models/threads/mixins/channel_seen_mixin.js
+++ b/addons/mail/static/src/js/models/threads/mixins/channel_seen_mixin.js
@@ -1,8 +1,6 @@
 odoo.define('mail.model.ChannelSeenMixin', function (require) {
 "use strict";
 
-var CCThrottleFunction = require('mail.model.CCThrottleFunction');
-
 var session = require('web.session');
 
 /**
@@ -25,12 +23,6 @@ var ChannelSeenMixin = {
     init: function (params) {
         this._seenPartnersInfo = params.data.seen_partners_info || [];
 
-        this._throttleNotifySeen = _.throttle(this._notifySeen.bind(this), 3000);
-        this._throttleNotifyFetched = CCThrottleFunction({
-            duration: 3000,
-            func: this._notifyFetched.bind(this),
-        });
-
         this.on('message_added', this, this._onSeenMessageAdded);
     },
 
@@ -225,27 +217,19 @@ var ChannelSeenMixin = {
     //--------------------------------------------------------------------------
 
     /**
-     * @private
-     */
-    _cancelThrottledNotifyFetched: function () {
-        this._throttleNotifyFetched.cancel();
-        this._throttleNotifyFetched.clear();
-    },
-    /**
-     * @abstract
-     * @private
-     * @returns {$.Promise}
-     */
-    _notifyFetched: function () {
-        return $.when();
-    },
-    /**
-     * @abstract
      * @private
      * @returns {$.Promise<integer>} resolved with ID of last seen message
      */
     _notifySeen: function () {
-        return $.when();
+        var self = this;
+        return this._rpc({
+            model: 'mail.channel',
+            method: 'channel_seen',
+            args: [[this._id]],
+        }, { shadow: true }).then(function (lastSeenMessageID) {
+            self._lastSeenMessageID = lastSeenMessageID;
+            return lastSeenMessageID;
+        });
     },
 
     //--------------------------------------------------------------------------
@@ -256,7 +240,7 @@ var ChannelSeenMixin = {
      * @private
      */
     _onSeenMessageAdded: function () {
-        this._throttleNotifyFetched();
+        this.call('mail_service', 'notifyChannelFetched', { channelID: this._id });
     },
 };
 
diff --git a/addons/mail/static/src/js/services/mail_manager.js b/addons/mail/static/src/js/services/mail_manager.js
index 6a49cdf0183..2234ce29af7 100644
--- a/addons/mail/static/src/js/services/mail_manager.js
+++ b/addons/mail/static/src/js/services/mail_manager.js
@@ -52,6 +52,12 @@ var MailManager =  AbstractService.extend({
      */
     start: function () {
         this._super.apply(this, arguments);
+
+        this._throttleNotifyChannelFetched = _.throttle(this._notifyChannelFetched.bind(this), 3000);
+        // List of channel that have requested the service to notify when
+        // it has been fetched, so that throttled RPCs batch the ids.
+        this._toNotifyChannelFetchedIDs = [];
+
         this._initializeInternalState();
         this._listenOnBuses();
         this._fetchMailStateFromServer();
@@ -337,6 +343,14 @@ var MailManager =  AbstractService.extend({
             return $.when();
         }
     },
+    /**
+     * @param {Object} data
+     * @param {integer} data.channelID
+     */
+    notifyChannelFetched: function (data) {
+        this._toNotifyChannelFetchedIDs = _.uniq(this._toNotifyChannelFetchedIDs.concat(data.channelID));
+        this._throttleNotifyChannelFetched();
+    },
     /**
      * @param {integer|string} threadID
      */
@@ -920,6 +934,23 @@ var MailManager =  AbstractService.extend({
     _makeMessage: function (data) {
         return new Message(this, data);
     },
+    /**
+     * @private
+     * @returns {$.Promise}
+     */
+    _notifyChannelFetched: function () {
+        var channelIDs = this._toNotifyChannelFetchedIDs;
+        this._toNotifyChannelFetchedIDs = [];
+        if (_.isEmpty(channelIDs)) {
+            // no channel to notify fetched
+            return $.when();
+        }
+        return this._rpc({
+            model: 'mail.channel',
+            method: 'channel_fetched',
+            args: [channelIDs],
+        }, { shadow: true });
+    },
     /**
      * shows a popup to notify a new received message.
      * This will also rename the browser tab if this is not the active tab.