diff --git a/addons/im_livechat/static/src/js/im_livechat.js b/addons/im_livechat/static/src/js/im_livechat.js
index fddf5ec6c2c..b392d337d04 100644
--- a/addons/im_livechat/static/src/js/im_livechat.js
+++ b/addons/im_livechat/static/src/js/im_livechat.js
@@ -237,6 +237,7 @@ var LivechatButton = Widget.extend({
             is_needaction: false,
             is_note: data.is_note,
             is_discussion: data.is_discussion,
+            is_notification: data.is_notification,
             customer_email_data: []
         };
 
diff --git a/addons/mail/models/mail_message.py b/addons/mail/models/mail_message.py
index 989167905fd..4362358b864 100644
--- a/addons/mail/models/mail_message.py
+++ b/addons/mail/models/mail_message.py
@@ -392,8 +392,9 @@ class Message(models.Model):
                     'message_type': u'comment',
                     'id': 59,
                     'subject': False
-                    'is_note': True # only if the subtype is internal
+                    'is_note': True # only if the message is a note (subtype == note)
                     'is_discussion': False # only if the message is a discussion (subtype == discussion)
+                    'is_notification': False # only if the message is a note but is a notification aka not linked to a document like assignation
                 }
         """
         message_values = self.read([
@@ -419,6 +420,7 @@ class Message(models.Model):
         for message in message_values:
             message['is_note'] = message['subtype_id'] and subtypes_dict[message['subtype_id'][0]]['id'] == note_id
             message['is_discussion'] = message['subtype_id'] and subtypes_dict[message['subtype_id'][0]]['id'] == com_id
+            message['is_notification'] = message['is_note'] and not message['model'] and not message['res_id']
             message['subtype_description'] = message['subtype_id'] and subtypes_dict[message['subtype_id'][0]]['description']
             if message['model'] and self.env[message['model']]._original_module:
                 message['module_icon'] = modules.module.get_module_icon(self.env[message['model']]._original_module)
diff --git a/addons/mail/static/src/js/services/chat_manager.js b/addons/mail/static/src/js/services/chat_manager.js
index ea6c9388f58..1abcd995084 100644
--- a/addons/mail/static/src/js/services/chat_manager.js
+++ b/addons/mail/static/src/js/services/chat_manager.js
@@ -1314,6 +1314,7 @@ var ChatManager =  AbstractService.extend({
      * @param  {string} [data.info]
      * @param  {boolean} data.is_discussion
      * @param  {boolean} data.is_note
+     * @param  {boolean} data.is_notification
      * @param  {string} data.message_type
      * @param  {string} [data.model]
      * @param  {boolean} data.module_icon src url of the module icon
@@ -1336,6 +1337,7 @@ var ChatManager =  AbstractService.extend({
             is_author: data.author_id && data.author_id[0] === session.partner_id,
             is_note: data.is_note,
             is_discussion: data.is_discussion,
+            is_notification: data.is_notification,
             is_system_notification: (data.message_type === 'notification' && data.model === 'mail.channel')
                 || data.info === 'transient_message',
             attachment_ids: data.attachment_ids || [],
diff --git a/addons/mail/static/src/xml/thread.xml b/addons/mail/static/src/xml/thread.xml
index 1019b141b75..118e96da8ff 100644
--- a/addons/mail/static/src/xml/thread.xml
+++ b/addons/mail/static/src/xml/thread.xml
@@ -121,7 +121,7 @@
     </t>
 
     <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' : '') + (message.is_discussion ? ' o_mail_discussion' : ' o_mail_not_discussion')" t-att-data-message-id="message.id">
+        <div t-att-class="'o_thread_message' + (message.expanded ? ' o_message_expanded '  : ' ') + (message.is_selected ? 'o_thread_selected_message' : '') + (message.is_discussion or message.is_notification ? ' o_mail_discussion' : ' o_mail_not_discussion')" t-att-data-message-id="message.id">
             <div t-if="options.display_avatar" class="o_thread_message_sidebar">
                 <t t-if="!message.mailto and message.author_id[0]">
                     <img t-if="message.avatar_src and message.display_author"
diff --git a/addons/mail/static/tests/chat_window_tests.js b/addons/mail/static/tests/chat_window_tests.js
index ab5a9f03538..05df8461d18 100644
--- a/addons/mail/static/tests/chat_window_tests.js
+++ b/addons/mail/static/tests/chat_window_tests.js
@@ -37,6 +37,7 @@ QUnit.module('mail', {
             id: 1,
             is_note: false,
             is_discussion: true,
+            is_notification: false,
             is_starred: false,
             model: 'partner',
             res_id: 2
diff --git a/addons/mail/static/tests/chatter_tests.js b/addons/mail/static/tests/chatter_tests.js
index 56ee5076479..8c1edc2f622 100644
--- a/addons/mail/static/tests/chatter_tests.js
+++ b/addons/mail/static/tests/chatter_tests.js
@@ -389,6 +389,7 @@ QUnit.test('chatter: post, receive and star messages', function (assert) {
         id: 1,
         is_note: false,
         is_discussion: true,
+        is_notification: false,
         is_starred: false,
         model: 'partner',
         res_id: 2,
@@ -433,6 +434,7 @@ QUnit.test('chatter: post, receive and star messages', function (assert) {
                     id: msg_id,
                     is_note: args.kwargs.subtype === 'mail.mt_note',
                     is_discussion: args.kwargs.subtype === 'mail.mt_comment',
+                    is_notification: false,
                     is_starred: false,
                     model: 'partner',
                     res_id: 2,