[REF] mail, various: rename subtype parameter of message_post to subtype_xmlid

PURPOSE

Clean posting process and improve mail.message definition and comprehension.

SPECIFICATIONS

In order to be more explicit subtype parameter is renamed to subtype_xmlid.
It therefore clearly indicates it should be a valid subtype Xml ID. Support
of ill formatted Xml IDs is removed because there is no reason to try to
add some random prefix. Give something that exists or go to hell, punk !

LINKS

Task ID 2071556
PR #38692

37 files changed, 101 insertions, 106 deletions

diff --git a/addons/calendar/models/calendar.py b/addons/calendar/models/calendar.py
index 98f25ab908a..97e131702ae 100644
--- a/addons/calendar/models/calendar.py
+++ b/addons/calendar/models/calendar.py
@@ -226,7 +226,7 @@ class Attendee(models.Model):
         result = self.write({'state': 'accepted'})
         for attendee in self:
             if attendee.event_id:
-                attendee.event_id.message_post(body=_("%s has accepted invitation") % (attendee.common_name), subtype="calendar.subtype_invitation")
+                attendee.event_id.message_post(body=_("%s has accepted invitation") % (attendee.common_name), subtype_xmlid="calendar.subtype_invitation")
         return result
 
     def do_decline(self):
@@ -234,7 +234,7 @@ class Attendee(models.Model):
         res = self.write({'state': 'declined'})
         for attendee in self:
             if attendee.event_id:
-                attendee.event_id.message_post(body=_("%s has declined invitation") % (attendee.common_name), subtype="calendar.subtype_invitation")
+                attendee.event_id.message_post(body=_("%s has declined invitation") % (attendee.common_name), subtype_xmlid="calendar.subtype_invitation")
         return res
 
 
diff --git a/addons/gamification/models/challenge.py b/addons/gamification/models/challenge.py
index 868e46d1fdf..50254967205 100644
--- a/addons/gamification/models/challenge.py
+++ b/addons/gamification/models/challenge.py
@@ -562,13 +562,13 @@ class Challenge(models.Model):
             challenge.message_post(
                 body=body_html,
                 partner_ids=challenge.mapped('user_ids.partner_id.id'),
-                subtype='mail.mt_comment',
+                subtype_xmlid='mail.mt_comment',
                 email_layout_xmlid='mail.mail_notification_light',
                 )
             if challenge.report_message_group_id:
                 challenge.report_message_group_id.message_post(
                     body=body_html,
-                    subtype='mail.mt_comment')
+                    subtype_xmlid='mail.mt_comment')
 
         else:
             # generate individual reports
@@ -586,13 +586,13 @@ class Challenge(models.Model):
                 challenge.message_notify(
                     body=body_html,
                     partner_ids=[user.partner_id.id],
-                    subtype='mail.mt_comment',
+                    subtype_xmlid='mail.mt_comment',
                     email_layout_xmlid='mail.mail_notification_light',
                 )
                 if challenge.report_message_group_id:
                     challenge.report_message_group_id.message_post(
                         body=body_html,
-                        subtype='mail.mt_comment',
+                        subtype_xmlid='mail.mt_comment',
                         email_layout_xmlid='mail.mail_notification_light',
                     )
         return challenge.write({'last_report_date': fields.Date.today()})
diff --git a/addons/gamification/models/goal.py b/addons/gamification/models/goal.py
index f78012d236b..80803449897 100644
--- a/addons/gamification/models/goal.py
+++ b/addons/gamification/models/goal.py
@@ -219,7 +219,7 @@ class Goal(models.Model):
         self.message_notify(
             body=body_html,
             partner_ids=[self.user_id.partner_id.id],
-            subtype='mail.mt_comment',
+            subtype_xmlid='mail.mt_comment',
             email_layout_xmlid='mail.mail_notification_light',
         )
 
diff --git a/addons/hr_holidays/models/hr_leave.py b/addons/hr_holidays/models/hr_leave.py
index b5d5c1a3458..6c05fc2c61e 100644
--- a/addons/hr_holidays/models/hr_leave.py
+++ b/addons/hr_holidays/models/hr_leave.py
@@ -666,7 +666,7 @@ class HolidaysRequest(models.Model):
                 # Automatic validation should be done in sudo, because user might not have the rights to do it by himself
                 holiday_sudo.action_validate()
                 holiday_sudo.message_subscribe(partner_ids=[holiday._get_responsible_for_approval().partner_id.id])
-                holiday_sudo.message_post(body=_("The time off has been automatically approved"), subtype="mt_comment") # Message from OdooBot (sudo)
+                holiday_sudo.message_post(body=_("The time off has been automatically approved"), subtype_xmlid="mail.mt_comment") # Message from OdooBot (sudo)
             elif not self._context.get('import_file'):
                 holiday_sudo.activity_update()
         return holiday
diff --git a/addons/hr_holidays/tests/test_access_rights.py b/addons/hr_holidays/tests/test_access_rights.py
index 1a8632f51a9..8781548ad27 100644
--- a/addons/hr_holidays/tests/test_access_rights.py
+++ b/addons/hr_holidays/tests/test_access_rights.py
@@ -608,7 +608,7 @@ class TestAccessRightsWrite(TestHrHolidaysAccessRightsCommon):
         """ User may communicate on its own leaves, even if validated """
         self.employee_leave.with_user(self.user_employee_id).message_post(
             body='I haz messaging',
-            subtype='mail.mt_comment',
+            subtype_xmlid='mail.mt_comment',
             message_type='comment'
         )
 
@@ -616,7 +616,7 @@ class TestAccessRightsWrite(TestHrHolidaysAccessRightsCommon):
 
         self.employee_leave.with_user(self.user_employee_id).message_post(
             body='I still haz messaging',
-            subtype='mail.mt_comment',
+            subtype_xmlid='mail.mt_comment',
             message_type='comment'
         )
 
diff --git a/addons/hr_recruitment/models/hr_recruitment.py b/addons/hr_recruitment/models/hr_recruitment.py
index ad0a2f32e84..2a6fca31b05 100644
--- a/addons/hr_recruitment/models/hr_recruitment.py
+++ b/addons/hr_recruitment/models/hr_recruitment.py
@@ -448,7 +448,7 @@ class Applicant(models.Model):
                     applicant.job_id.write({'no_of_hired_employee': applicant.job_id.no_of_hired_employee + 1})
                     applicant.job_id.message_post(
                         body=_('New Employee %s Hired') % applicant.partner_name if applicant.partner_name else applicant.name,
-                        subtype="hr_recruitment.mt_job_applicant_hired")
+                        subtype_xmlid="hr_recruitment.mt_job_applicant_hired")
                 applicant.message_post_with_view(
                     'hr_recruitment.applicant_hired_template',
                     values={'applicant': applicant},
diff --git a/addons/mail/controllers/bus.py b/addons/mail/controllers/bus.py
index 81f1700987d..ccbe6bdeb5f 100644
--- a/addons/mail/controllers/bus.py
+++ b/addons/mail/controllers/bus.py
@@ -53,7 +53,7 @@ class MailChatController(BusController):
         message = mail_channel.with_context(mail_create_nosubscribe=True).message_post(author_id=author_id,
                                                                                        email_from=email_from, body=body,
                                                                                        message_type='comment',
-                                                                                       subtype='mail.mt_comment')
+                                                                                       subtype_xmlid='mail.mt_comment')
         return message and message.id or False
 
     @route(['/mail/chat_history'], type="json", auth="public", cors="*")
diff --git a/addons/mail/controllers/home.py b/addons/mail/controllers/home.py
index b4c4bd5d93d..9d54b6ebd1c 100644
--- a/addons/mail/controllers/home.py
+++ b/addons/mail/controllers/home.py
@@ -27,7 +27,7 @@ def _admin_password_warn(uid):
         .message_post(
             body=_("Your password is the default (admin)! If this system is exposed to untrusted users it is important to change it immediately for security reasons. I will keep nagging you about it!"),
             message_type='comment',
-            subtype='mail.mt_comment'
+            subtype_xmlid='mail.mt_comment'
         )
 
 class Home(web.Home):
diff --git a/addons/mail/models/mail_channel.py b/addons/mail/models/mail_channel.py
index 2d3c54a9591..f78a415b522 100644
--- a/addons/mail/models/mail_channel.py
+++ b/addons/mail/models/mail_channel.py
@@ -280,7 +280,7 @@ class Channel(models.Model):
         if not self.email_send:
             notification = _('<div class="o_mail_notification">left <a href="#" class="o_channel_redirect" data-oe-id="%s">#%s</a></div>') % (self.id, self.name,)
             # post 'channel left' message as root since the partner just unsubscribed from the channel
-            self.sudo().message_post(body=notification, subtype="mail.mt_comment", author_id=partner.id)
+            self.sudo().message_post(body=notification, subtype_xmlid="mail.mt_comment", author_id=partner.id)
         return result
 
     def _notify_get_groups(self):
@@ -780,7 +780,7 @@ class Channel(models.Model):
                     }
                 else:
                     notification = _('<div class="o_mail_notification">joined <a href="#" class="o_channel_redirect" data-oe-id="%s">#%s</a></div>') % (channel.id, channel.name,)
-                self.message_post(body=notification, message_type="notification", subtype="mail.mt_comment", author_id=partner.id)
+                self.message_post(body=notification, message_type="notification", subtype_xmlid="mail.mt_comment", author_id=partner.id)
 
         # broadcast the channel header to the added partner
         self._broadcast(partner_ids)
@@ -861,7 +861,7 @@ class Channel(models.Model):
         added = self.action_follow()
         if added and self.channel_type == 'channel' and not self.email_send:
             notification = _('<div class="o_mail_notification">joined <a href="#" class="o_channel_redirect" data-oe-id="%s">#%s</a></div>') % (self.id, self.name,)
-            self.message_post(body=notification, message_type="notification", subtype="mail.mt_comment")
+            self.message_post(body=notification, message_type="notification", subtype_xmlid="mail.mt_comment")
 
         if added and self.moderation_guidelines:
             self._send_guidelines(self.env.user.partner_id)
@@ -886,7 +886,7 @@ class Channel(models.Model):
             'channel_partner_ids': [(4, self.env.user.partner_id.id)]
         })
         notification = _('<div class="o_mail_notification">created <a href="#" class="o_channel_redirect" data-oe-id="%s">#%s</a></div>') % (new_channel.id, new_channel.name,)
-        new_channel.message_post(body=notification, message_type="notification", subtype="mail.mt_comment")
+        new_channel.message_post(body=notification, message_type="notification", subtype_xmlid="mail.mt_comment")
         channel_info = new_channel.channel_info('creation')[0]
         self.env['bus.bus'].sendone((self._cr.dbname, 'res.partner', self.env.user.partner_id.id), channel_info)
         return channel_info
diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 5e662e9db00..a4abcaae227 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -1777,7 +1777,7 @@ class MailThread(models.AbstractModel):
     def message_post(self, *,
                      body='', subject=None, message_type='notification',
                      email_from=None, author_id=None, parent_id=False,
-                     subtype_id=False, subtype=None, partner_ids=None, channel_ids=None,
+                     subtype_xmlid=None, subtype_id=False, partner_ids=None, channel_ids=None,
                      attachments=None, attachment_ids=None,
                      add_sign=True, record_name=False,
                      **kwargs):
@@ -1791,8 +1791,6 @@ class MailThread(models.AbstractModel):
             :param int parent_id: handle thread formation
             :param int subtype_id: subtype_id of the message, mainly use fore
                 followers mechanism
-            :param int subtype: xmlid that will be used to compute subtype_id
-                if subtype_id is not given.
             :param list(int) partner_ids: partner_ids to notify
             :param list(int) channel_ids: channel_ids to notify
             :param list(tuple(str,str), tuple(str,str, dict) or int) attachments : list of attachment tuples in the form
@@ -1814,7 +1812,9 @@ class MailThread(models.AbstractModel):
             raise ValueError('message_post should only be call to post message on record. Use message_notify instead')
 
         if 'model' in msg_kwargs or 'res_id' in msg_kwargs:
-            raise ValueError("message_post doesn't support model and res_id parameters anymore. Please call message_post on record")
+            raise ValueError("message_post doesn't support model and res_id parameters anymore. Please call message_post on record.")
+        if 'subtype' in kwargs:
+            raise ValueError("message_post doesn't support subtype parameter anymore. Please give a valid subtype_id or subtype_xmlid value instead.")
 
         self = self.with_lang() # add lang to context imediatly since it will be usefull in various flows latter.
 
@@ -1832,11 +1832,10 @@ class MailThread(models.AbstractModel):
         # Find the message's author
         author_id, email_from = self._message_compute_author(author_id, email_from, raise_exception=True)
 
+        if subtype_xmlid:
+            subtype_id = self.env['ir.model.data'].xmlid_to_res_id(subtype_xmlid)
         if not subtype_id:
-            subtype = subtype or 'mt_note'
-            if '.' not in subtype:
-                subtype = 'mail.%s' % subtype
-            subtype_id = self.env['ir.model.data'].xmlid_to_res_id(subtype)
+            subtype_id = self.env['ir.model.data'].xmlid_to_res_id('mail_mt_note')
 
         # automatically subscribe recipients if asked to
         if self._context.get('mail_post_autofollow') and partner_ids:
diff --git a/addons/mail/models/update.py b/addons/mail/models/update.py
index 573709a1377..edf5b4f2ced 100644
--- a/addons/mail/models/update.py
+++ b/addons/mail/models/update.py
@@ -104,7 +104,7 @@ class PublisherWarrantyContract(AbstractModel):
                 poster = user
             for message in result["messages"]:
                 try:
-                    poster.message_post(body=message, subtype='mt_comment', partner_ids=[user.partner_id.id])
+                    poster.message_post(body=message, subtype_xmlid='mail.mt_comment', partner_ids=[user.partner_id.id])
                 except Exception:
                     pass
             if result.get('enterprise_info'):
diff --git a/addons/mail/static/src/js/composers/chatter_composer.js b/addons/mail/static/src/js/composers/chatter_composer.js
index 4b20e5b2d25..04a01142ff3 100644
--- a/addons/mail/static/src/js/composers/chatter_composer.js
+++ b/addons/mail/static/src/js/composers/chatter_composer.js
@@ -205,14 +205,14 @@ var ChatterComposer = BasicComposer.extend({
         return new Promise(function (resolve, reject) {
             self._super().then(function (message) {
                 message = _.extend(message, {
-                    subtype: 'mail.mt_comment',
+                    subtype_xmlid: 'mail.mt_comment',
                     message_type: 'comment',
                     context: _.defaults({}, self.context, session.user_context),
                 });
 
                 // Subtype
                 if (self.options.isLog) {
-                    message.subtype = 'mail.mt_note';
+                    message.subtype_xmlid = 'mail.mt_note';
                 }
 
                 // Partner_ids
diff --git a/addons/mail/static/src/js/discuss.js b/addons/mail/static/src/js/discuss.js
index 3d8eda911be..0f2b7feff26 100644
--- a/addons/mail/static/src/js/discuss.js
+++ b/addons/mail/static/src/js/discuss.js
@@ -1496,7 +1496,7 @@ var Discuss = AbstractAction.extend({
         var self = this;
         var options = {};
         if (this._selectedMessage) {
-            messageData.subtype = this._selectedMessage.isNote() ? 'mail.mt_note': 'mail.mt_comment';
+            messageData.subtype_xmlid = this._selectedMessage.isNote() ? 'mail.mt_note': 'mail.mt_comment';
             messageData.subtype_id = false;
             messageData.message_type = 'comment';
 
diff --git a/addons/mail/static/src/js/models/threads/channel.js b/addons/mail/static/src/js/models/threads/channel.js
index 6301018c01f..a47598e3147 100644
--- a/addons/mail/static/src/js/models/threads/channel.js
+++ b/addons/mail/static/src/js/models/threads/channel.js
@@ -443,7 +443,7 @@ var Channel = SearchableThread.extend(ThreadTypingMixin, {
         return this._super.apply(this, arguments).then(function (messageData) {
             _.extend(messageData, {
                 message_type: 'comment',
-                subtype: 'mail.mt_comment',
+                subtype_xmlid: 'mail.mt_comment',
                 command: data.command,
             });
             return self._rpc({
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 cb860b70beb..eefc8f9bd79 100644
--- a/addons/mail/static/src/js/models/threads/document_thread.js
+++ b/addons/mail/static/src/js/models/threads/document_thread.js
@@ -331,7 +331,7 @@ var DocumentThread = Thread.extend({
                 _.extend(messageData, {
                     context: data.context,
                     message_type: data.message_type,
-                    subtype: data.subtype || "mail.mt_comment",
+                    subtype_xmlid: data.subtype_xmlid || "mail.mt_comment",
                     subtype_id: data.subtype_id,
                 });
                 return self._rpc({
diff --git a/addons/mail/static/tests/chatter_tests.js b/addons/mail/static/tests/chatter_tests.js
index d39be2af342..c108738bf94 100644
--- a/addons/mail/static/tests/chatter_tests.js
+++ b/addons/mail/static/tests/chatter_tests.js
@@ -1008,8 +1008,8 @@ QUnit.test('chatter: post, receive and star messages', async function (assert) {
                     body: args.kwargs.body,
                     date: "2016-12-20 10:35:40",
                     id: messageID,
-                    is_note: args.kwargs.subtype === 'mail.mt_note',
-                    is_discussion: args.kwargs.subtype === 'mail.mt_comment',
+                    is_note: args.kwargs.subtype_xmlid === 'mail.mt_note',
+                    is_discussion: args.kwargs.subtype_xmlid === 'mail.mt_comment',
                     is_notification: false,
                     is_starred: false,
                     model: 'partner',
@@ -1403,8 +1403,8 @@ QUnit.test('chatter: post a message and switch in edit mode', async function (as
                     body: args.kwargs.body,
                     date: "2016-12-20 10:35:40",
                     id: 42,
-                    is_note: args.kwargs.subtype === 'mail.mt_note',
-                    is_discussion: args.kwargs.subtype === 'mail.mt_comment',
+                    is_note: args.kwargs.subtype_xmlid === 'mail.mt_note',
+                    is_discussion: args.kwargs.subtype_xmlid === 'mail.mt_comment',
                     is_starred: false,
                     model: 'partner',
                     res_id: 2,
@@ -3061,8 +3061,8 @@ QUnit.test('chatter: suggested partner auto-follow on message post', async funct
                     body: args.kwargs.body,
                     date: "2016-12-20 10:35:40",
                     id: messageID,
-                    is_note: args.kwargs.subtype === 'mail.mt_note',
-                    is_discussion: args.kwargs.subtype === 'mail.mt_comment',
+                    is_note: args.kwargs.subtype_xmlid === 'mail.mt_note',
+                    is_discussion: args.kwargs.subtype_xmlid === 'mail.mt_comment',
                     is_notification: false,
                     is_starred: false,
                     model: 'partner',
diff --git a/addons/mail_bot/models/mail_channel.py b/addons/mail_bot/models/mail_channel.py
index 0fc6c6f056b..8b792780971 100644
--- a/addons/mail_bot/models/mail_channel.py
+++ b/addons/mail_bot/models/mail_channel.py
@@ -24,6 +24,6 @@ class Channel(models.Model):
                 'name': 'OdooBot'
             })
             message = _("Hello,<br/>Odoo's chat helps employees collaborate efficiently. I'm here to help you discover its features.<br/><b>Try to send me an emoji :)</b>")
-            channel.sudo().message_post(body=message, author_id=odoobot_id, message_type="comment", subtype="mail.mt_comment")
+            channel.sudo().message_post(body=message, author_id=odoobot_id, message_type="comment", subtype_xmlid="mail.mt_comment")
             self.env.user.odoobot_state = 'onboarding_emoji'
             return channel
diff --git a/addons/portal/controllers/mail.py b/addons/portal/controllers/mail.py
index 63999697ff3..eddf8cb32ce 100644
--- a/addons/portal/controllers/mail.py
+++ b/addons/portal/controllers/mail.py
@@ -86,7 +86,7 @@ def _message_post_helper(res_model, res_id, message, token='', _hash=False, pid=
     message_post_args = dict(
         body=message,
         message_type=kw.pop('message_type', "comment"),
-        subtype=kw.pop('subtype', "mt_comment"),
+        subtype_xmlid=kw.pop('subtype_xmlid', "mail.mt_comment"),
         author_id=author_id,
         **kw
     )
diff --git a/addons/project/models/project.py b/addons/project/models/project.py
index e97754be5b8..decb61cc94b 100644
--- a/addons/project/models/project.py
+++ b/addons/project/models/project.py
@@ -930,8 +930,8 @@ class Task(models.Model):
             return self.project_id.partner_id
         return res
 
-    def rating_apply(self, rate, token=None, feedback=None, subtype=None):
-        return super(Task, self).rating_apply(rate, token=token, feedback=feedback, subtype="project.mt_task_rating")
+    def rating_apply(self, rate, token=None, feedback=None, subtype_xmlid=None):
+        return super(Task, self).rating_apply(rate, token=token, feedback=feedback, subtype_xmlid="project.mt_task_rating")
 
     def _rating_get_parent_field_name(self):
         return 'project_id'
diff --git a/addons/rating/models/rating_mixin.py b/addons/rating/models/rating_mixin.py
index 77196e80c50..62fa232f12f 100644
--- a/addons/rating/models/rating_mixin.py
+++ b/addons/rating/models/rating_mixin.py
@@ -168,7 +168,7 @@ class RatingMixin(models.AbstractModel):
                 subtype_id=subtype_id
             )
 
-    def rating_apply(self, rate, token=None, feedback=None, subtype=None):
+    def rating_apply(self, rate, token=None, feedback=None, subtype_xmlid=None):
         """ Apply a rating given a token. If the current model inherits from
         mail.thread mixin, a message is posted on its chatter. User going through
         this method should have at least employee rights because of rating
@@ -178,7 +178,7 @@ class RatingMixin(models.AbstractModel):
         :param float rate : the rating value to apply
         :param string token : access token
         :param string feedback : additional feedback
-        :param string subtype : xml id of a valid mail.message.subtype
+        :param string subtype_xmlid : xml id of a valid mail.message.subtype
 
         :returns rating.rating record
         """
@@ -194,7 +194,7 @@ class RatingMixin(models.AbstractModel):
                 self.message_post(
                     body="<img src='/rating/static/src/img/rating_%s.png' alt=':%s/10' style='width:18px;height:18px;float:left;margin-right: 5px;'/>%s"
                     % (rate, rate, feedback),
-                    subtype=subtype or "mail.mt_comment",
+                    subtype_xmlid=subtype_xmlid or "mail.mt_comment",
                     author_id=rating.partner_id and rating.partner_id.id or None  # None will set the default author in mail_thread.py
                 )
             if hasattr(self, 'stage_id') and self.stage_id and hasattr(self.stage_id, 'auto_validation_kanban_state') and self.stage_id.auto_validation_kanban_state:
diff --git a/addons/sale/controllers/portal.py b/addons/sale/controllers/portal.py
index 52495a93316..e951dce54b2 100644
--- a/addons/sale/controllers/portal.py
+++ b/addons/sale/controllers/portal.py
@@ -159,7 +159,7 @@ class CustomerPortal(CustomerPortal):
         if order_sudo and request.session.get('view_quote_%s' % order_sudo.id) != now and request.env.user.share and access_token:
             request.session['view_quote_%s' % order_sudo.id] = now
             body = _('Quotation viewed by customer %s') % order_sudo.partner_id.name
-            _message_post_helper('sale.order', order_sudo.id, body, token=order_sudo.access_token, message_type='notification', subtype="mail.mt_note")
+            _message_post_helper('sale.order', order_sudo.id, body, token=order_sudo.access_token, message_type='notification', subtype_xmlid="mail.mt_note")
 
         values = {
             'sale_order': order_sudo,
diff --git a/addons/test_mail/tests/test_discuss.py b/addons/test_mail/tests/test_discuss.py
index 5667568ead0..e2bda7dc8d9 100644
--- a/addons/test_mail/tests/test_discuss.py
+++ b/addons/test_mail/tests/test_discuss.py
@@ -15,7 +15,7 @@ class TestChatterTweaks(TestMailCommon, TestRecipients):
     def test_post_no_subscribe_author(self):
         original = self.test_record.message_follower_ids
         self.test_record.with_user(self.user_employee).with_context({'mail_create_nosubscribe': True}).message_post(
-            body='Test Body', message_type='comment', subtype='mt_comment')
+            body='Test Body', message_type='comment', subtype_xmlid='mail.mt_comment')
         self.assertEqual(self.test_record.message_follower_ids.mapped('partner_id'), original.mapped('partner_id'))
         self.assertEqual(self.test_record.message_follower_ids.mapped('channel_id'), original.mapped('channel_id'))
 
@@ -23,7 +23,7 @@ class TestChatterTweaks(TestMailCommon, TestRecipients):
     def test_post_no_subscribe_recipients(self):
         original = self.test_record.message_follower_ids
         self.test_record.with_user(self.user_employee).with_context({'mail_create_nosubscribe': True}).message_post(
-            body='Test Body', message_type='comment', subtype='mt_comment', partner_ids=[self.partner_1.id, self.partner_2.id])
+            body='Test Body', message_type='comment', subtype_xmlid='mail.mt_comment', partner_ids=[self.partner_1.id, self.partner_2.id])
         self.assertEqual(self.test_record.message_follower_ids.mapped('partner_id'), original.mapped('partner_id'))
         self.assertEqual(self.test_record.message_follower_ids.mapped('channel_id'), original.mapped('channel_id'))
 
@@ -31,7 +31,7 @@ class TestChatterTweaks(TestMailCommon, TestRecipients):
     def test_post_subscribe_recipients(self):
         original = self.test_record.message_follower_ids
         self.test_record.with_user(self.user_employee).with_context({'mail_create_nosubscribe': True, 'mail_post_autofollow': True}).message_post(
-            body='Test Body', message_type='comment', subtype='mt_comment', partner_ids=[self.partner_1.id, self.partner_2.id])
+            body='Test Body', message_type='comment', subtype_xmlid='mail.mt_comment', partner_ids=[self.partner_1.id, self.partner_2.id])
         self.assertEqual(self.test_record.message_follower_ids.mapped('partner_id'), original.mapped('partner_id') | self.partner_1 | self.partner_2)
         self.assertEqual(self.test_record.message_follower_ids.mapped('channel_id'), original.mapped('channel_id'))
 
@@ -100,7 +100,7 @@ class TestDiscuss(TestMailCommon, TestRecipients):
     def test_set_message_done_user(self):
         with self.assertSinglePostNotifications([{'partner': self.partner_employee, 'type': 'inbox'}], message_info={'content': 'Test'}):
             message = self.test_record.message_post(
-                body='Test', message_type='comment', subtype='mail.mt_comment',
+                body='Test', message_type='comment', subtype_xmlid='mail.mt_comment',
                 partner_ids=[self.user_employee.partner_id.id])
         message.with_user(self.user_employee).set_message_done()
         self.assertMailNotifications(message, [{'notif': [{'partner': self.partner_employee, 'type': 'inbox', 'is_read': True}]}])
diff --git a/addons/test_mail/tests/test_mail_channel.py b/addons/test_mail/tests/test_mail_channel.py
index 5dadf2690b7..8869ac21442 100644
--- a/addons/test_mail/tests/test_mail_channel.py
+++ b/addons/test_mail/tests/test_mail_channel.py
@@ -149,7 +149,7 @@ class TestChannelFeatures(TestMailCommon):
         self.assertEqual(self.test_channel.channel_partner_ids, self.env['res.partner'])
 
     def test_channel_post_nofollow(self):
-        self.test_channel.message_post(body='Test', message_type='comment', subtype='mt_comment')
+        self.test_channel.message_post(body='Test', message_type='comment', subtype_xmlid='mail.mt_comment')
         self.assertEqual(self.test_channel.message_channel_ids, self.test_channel)
         self.assertEqual(self.test_channel.message_partner_ids, self.env['res.partner'])
 
@@ -168,7 +168,7 @@ class TestChannelFeatures(TestMailCommon):
         })
         self._join_channel(self.test_channel, self.user_employee.partner_id | self.test_partner | nomail.partner_id)
         with self.mock_mail_gateway():
-            self.test_channel.message_post(body="Test", message_type='comment', subtype='mt_comment')
+            self.test_channel.message_post(body="Test", message_type='comment', subtype_xmlid='mail.mt_comment')
         self.assertSentEmail(self.test_channel.env.user.partner_id, [self.partner_employee, self.test_partner])
 
     @mute_logger('odoo.addons.mail.models.mail_mail', 'odoo.models.unlink')
@@ -178,7 +178,7 @@ class TestChannelFeatures(TestMailCommon):
         self.test_channel.write({'email_send': False})
         self._join_channel(self.test_channel, self.user_employee.partner_id | self.test_partner)
         with self.mock_mail_gateway():
-            self.test_channel.message_post(body="Test", message_type='comment', subtype='mt_comment')
+            self.test_channel.message_post(body="Test", message_type='comment', subtype_xmlid='mail.mt_comment')
         self.assertNotSentEmail()
         self.assertEqual(len(self._mails), 0)
 
@@ -188,7 +188,7 @@ class TestChannelFeatures(TestMailCommon):
         self.test_channel.write({'alias_name': False})
         self.test_channel.message_subscribe([self.user_employee.partner_id.id, self.test_partner.id])
         with self.mock_mail_gateway():
-            self.test_channel.message_post(body="Test", message_type='comment', subtype='mt_comment')
+            self.test_channel.message_post(body="Test", message_type='comment', subtype_xmlid='mail.mt_comment')
         self.assertSentEmail(self.test_channel.env.user.partner_id, [self.test_partner])
 
     @mute_logger('odoo.addons.mail.models.mail_mail')
@@ -323,10 +323,10 @@ class TestChannelModeration(TestMailCommon):
         self.channel_1._update_moderation_email([email1], 'ban')
         self.channel_1._update_moderation_email([email2], 'allow')
 
-        msg_admin = self.channel_1.message_post(message_type='email', subtype='mt_comment', author_id=self.partner_admin.id)
-        msg_moderator = self.channel_1.message_post(message_type='comment', subtype='mt_comment', author_id=self.partner_employee.id)
-        msg_email1 = self.channel_1.message_post(message_type='comment', subtype='mt_comment', email_from=formataddr(("MyName", email1)))
-        msg_email2 = self.channel_1.message_post(message_type='email', subtype='mt_comment', email_from=email2)
+        msg_admin = self.channel_1.message_post(message_type='email', subtype_xmlid='mail.mt_comment', author_id=self.partner_admin.id)
+        msg_moderator = self.channel_1.message_post(message_type='comment', subtype_xmlid='mail.mt_comment', author_id=self.partner_employee.id)
+        msg_email1 = self.channel_1.message_post(message_type='comment', subtype_xmlid='mail.mt_comment', email_from=formataddr(("MyName", email1)))
+        msg_email2 = self.channel_1.message_post(message_type='email', subtype_xmlid='mail.mt_comment', email_from=email2)
         msg_notif = self.channel_1.message_post()
 
         messages = self.env['mail.message'].search([('model', '=', 'mail.channel'), ('res_id', '=', self.channel_1.id)])
diff --git a/addons/test_mail/tests/test_mail_gateway.py b/addons/test_mail/tests/test_mail_gateway.py
index 9850243ba7c..d9da245a1e0 100644
--- a/addons/test_mail/tests/test_mail_gateway.py
+++ b/addons/test_mail/tests/test_mail_gateway.py
@@ -626,14 +626,14 @@ class TestMailgateway(TestMailCommon):
         record_msg = first_record.message_post(
             subject='Discussion',
             no_auto_thread=False,
-            subtype='mail.mt_comment',
+            subtype_xmlid='mail.mt_comment',
         )
         self.assertEqual(record_msg.reply_to, formataddr(('%s %s' % (self.user_employee.company_id.name, first_record.name), '%s@%s' % ('catchall.test', 'test.com'))))
         mail_msg = first_record.message_post(
             subject='Replies to Record',
             reply_to='groups@test.com',
             no_auto_thread=True,
-            subtype='mail.mt_comment',
+            subtype_xmlid='mail.mt_comment',
         )
         self.assertEqual(mail_msg.reply_to, 'groups@test.com')
 
diff --git a/addons/test_mail/tests/test_mail_message.py b/addons/test_mail/tests/test_mail_message.py
index 3f433496f4e..4f08f0abc18 100644
--- a/addons/test_mail/tests/test_mail_message.py
+++ b/addons/test_mail/tests/test_mail_message.py
@@ -360,13 +360,13 @@ class TestMessageAccess(TestMailCommon):
         ).with_context({'mail_create_nosubscribe': False})
 
         # mark all as read clear needactions
-        group_private.message_post(body='Test', message_type='comment', subtype='mail.mt_comment', partner_ids=[emp_partner.id])
+        group_private.message_post(body='Test', message_type='comment', subtype_xmlid='mail.mt_comment', partner_ids=[emp_partner.id])
         emp_partner.env['mail.message'].mark_all_as_read(domain=[])
         na_count = emp_partner.get_needaction_count()
         self.assertEqual(na_count, 0, "mark all as read should conclude all needactions")
 
         # mark all as read also clear inaccessible needactions
-        new_msg = group_private.message_post(body='Zest', message_type='comment', subtype='mail.mt_comment', partner_ids=[emp_partner.id])
+        new_msg = group_private.message_post(body='Zest', message_type='comment', subtype_xmlid='mail.mt_comment', partner_ids=[emp_partner.id])
         needaction_accessible = len(emp_partner.env['mail.message'].search([['needaction', '=', True]]))
         self.assertEqual(needaction_accessible, 1, "a new message to a partner is readable to that partner")
 
@@ -388,13 +388,13 @@ class TestMessageAccess(TestMailCommon):
         portal_partner = self.user_portal.partner_id.with_user(self.user_portal)
 
         # mark all as read clear needactions
-        self.group_pigs.message_post(body='Test', message_type='comment', subtype='mail.mt_comment', partner_ids=[portal_partner.id])
+        self.group_pigs.message_post(body='Test', message_type='comment', subtype_xmlid='mail.mt_comment', partner_ids=[portal_partner.id])
         portal_partner.env['mail.message'].mark_all_as_read(domain=[])
         na_count = portal_partner.get_needaction_count()
         self.assertEqual(na_count, 0, "mark all as read should conclude all needactions")
 
         # mark all as read also clear inaccessible needactions
-        new_msg = self.group_pigs.message_post(body='Zest', message_type='comment', subtype='mail.mt_comment', partner_ids=[portal_partner.id])
+        new_msg = self.group_pigs.message_post(body='Zest', message_type='comment', subtype_xmlid='mail.mt_comment', partner_ids=[portal_partner.id])
         needaction_accessible = len(portal_partner.env['mail.message'].search([['needaction', '=', True]]))
         self.assertEqual(needaction_accessible, 1, "a new message to a partner is readable to that partner")
 
diff --git a/addons/test_mail/tests/test_message_management.py b/addons/test_mail/tests/test_message_management.py
index cc3cb367574..b2c437ce2db 100644
--- a/addons/test_mail/tests/test_message_management.py
+++ b/addons/test_mail/tests/test_message_management.py
@@ -36,7 +36,7 @@ class TestMailResend(TestMailCommon):
                 [{'partner': partner, 'type': 'email', 'status': 'exception'} for partner in self.partners],
                 message_info={'message_type': 'notification'},
                 sim_error='connect_failure'):
-            message = self.test_record.with_user(self.user_admin).message_post(partner_ids=self.partners.ids, subtype='mail.mt_comment', message_type='notification')
+            message = self.test_record.with_user(self.user_admin).message_post(partner_ids=self.partners.ids, subtype_xmlid='mail.mt_comment', message_type='notification')
 
         wizard = self.env['mail.resend.message'].with_context({'mail_message_to_resend': message.id}).create({})
         self.assertEqual(wizard.notification_ids.mapped('res_partner_id'), self.partners, "wizard should manage notifications for each failed partner")
@@ -80,7 +80,7 @@ class TestMailResend(TestMailCommon):
     def test_remove_mail_become_canceled(self):
         # two failure sent on bus, one for each mail
         with self.mock_mail_gateway(), self.assertBus([(self.cr.dbname, 'res.partner', self.partner_admin.id)] * 2):
-            message = self.test_record.with_user(self.user_admin).message_post(partner_ids=self.partners.ids, subtype='mail.mt_comment', message_type='notification')
+            message = self.test_record.with_user(self.user_admin).message_post(partner_ids=self.partners.ids, subtype_xmlid='mail.mt_comment', message_type='notification')
 
         self.assertMailNotifications(message, [
             {'content': '', 'message_type': 'notification',
@@ -102,7 +102,7 @@ class TestMailResend(TestMailCommon):
     @mute_logger('odoo.addons.mail.models.mail_mail')
     def test_cancel_all(self):
         with self.mock_mail_gateway(), self.assertBus([(self.cr.dbname, 'res.partner', self.partner_admin.id)] * 2):
-            message = self.test_record.with_user(self.user_admin).message_post(partner_ids=self.partners.ids, subtype='mail.mt_comment', message_type='notification')
+            message = self.test_record.with_user(self.user_admin).message_post(partner_ids=self.partners.ids, subtype_xmlid='mail.mt_comment', message_type='notification')
 
         wizard = self.env['mail.resend.message'].with_context({'mail_message_to_resend': message.id}).create({})
         # one update for cancell
diff --git a/addons/test_mail/tests/test_message_post.py b/addons/test_mail/tests/test_message_post.py
index bf894fafe12..8e0a06320fb 100644
--- a/addons/test_mail/tests/test_message_post.py
+++ b/addons/test_mail/tests/test_message_post.py
@@ -27,7 +27,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
         (self.user_employee | self.user_admin).write({'notification_type': 'inbox'})
         with self.assertSinglePostNotifications([{'partner': self.partner_employee, 'type': 'inbox'}], {'content': 'Body'}):
             self.test_record.message_post(
-                body='Body', message_type='comment', subtype='mail.mt_comment',
+                body='Body', message_type='comment', subtype_xmlid='mail.mt_comment',
                 partner_ids=[self.user_employee.partner_id.id])
 
         self.test_record.message_subscribe([self.partner_1.id])
@@ -35,14 +35,14 @@ class TestMessagePost(TestMailCommon, TestRecipients):
                 {'partner': self.partner_employee, 'type': 'inbox'},
                 {'partner': self.partner_1, 'type': 'email'}], {'content': 'NewBody'}):
             self.test_record.message_post(
-                body='NewBody', message_type='comment', subtype='mail.mt_comment',
+                body='NewBody', message_type='comment', subtype_xmlid='mail.mt_comment',
                 partner_ids=[self.user_employee.partner_id.id])
 
         with self.assertSinglePostNotifications([
                 {'partner': self.partner_1, 'type': 'email'},
                 {'partner': self.partner_portal, 'type': 'email'}], {'content': 'ToPortal'}):
             self.test_record.message_post(
-                body='ToPortal', message_type='comment', subtype='mail.mt_comment',
+                body='ToPortal', message_type='comment', subtype_xmlid='mail.mt_comment',
                 partner_ids=[self.partner_portal.id])
 
     def test_post_inactive_follower(self):
@@ -52,14 +52,14 @@ class TestMessagePost(TestMailCommon, TestRecipients):
         self.test_record._message_subscribe(self.user_employee.partner_id.ids)
         with self.assertSinglePostNotifications([{'partner': self.partner_employee, 'type': 'inbox'}], {'content': 'Test'}):
             self.test_record.message_post(
-                body='Test', message_type='comment', subtype='mail.mt_comment')
+                body='Test', message_type='comment', subtype_xmlid='mail.mt_comment')
 
         self.user_employee.active = False
         # at this point, partner is still active and would receive an email notification
         self.user_employee.partner_id._write({'active': False})
         with self.assertPostNotifications([{'content': 'Test', 'notif': []}]):
             self.test_record.message_post(
-                body='Test', message_type='comment', subtype='mail.mt_comment')
+                body='Test', message_type='comment', subtype_xmlid='mail.mt_comment')
 
     @mute_logger('odoo.addons.mail.models.mail_mail')
     def test_post_notifications(self):
@@ -74,7 +74,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
                 {'partner': self.partner_admin, 'type': 'email'}], {'content': _body}, mail_unlink_sent=True):
             msg = self.test_record.with_user(self.user_employee).message_post(
                 body=_body, subject=_subject,
-                message_type='comment', subtype='mt_comment',
+                message_type='comment', subtype_xmlid='mail.mt_comment',
                 partner_ids=[self.partner_1.id, self.partner_2.id]
             )
 
@@ -95,7 +95,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
 
         msg = self.test_record.with_user(self.user_employee).message_post(
             body='Test', subject='Test',
-            message_type='comment', subtype='mt_comment',
+            message_type='comment', subtype_xmlid='mail.mt_comment',
             partner_ids=[self.partner_1.id, self.partner_2.id],
             mail_auto_delete=False
         )
@@ -126,7 +126,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
         with self.mock_mail_gateway():
             msg = self.test_record.with_user(self.user_employee).message_post(
                 body='Test', subject='Test',
-                message_type='comment', subtype='mt_comment',
+                message_type='comment', subtype_xmlid='mail.mt_comment',
                 attachment_ids=[_attach_1.id, _attach_2.id],
                 partner_ids=[self.partner_1.id],
                 attachments=_attachments,
@@ -155,7 +155,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
         with self.mock_mail_gateway():
             parent_msg = self.test_record.with_user(self.user_employee).message_post(
                 body='<p>Test</p>', subject='Test Subject',
-                message_type='comment', subtype='mt_comment')
+                message_type='comment', subtype_xmlid='mail.mt_comment')
 
         self.assertEqual(parent_msg.partner_ids, self.env['res.partner'])
         self.assertNotSentEmail()
@@ -163,7 +163,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
         with self.assertPostNotifications([{'content': '<p>Test Answer</p>', 'notif': [{'partner': self.partner_1, 'type': 'email'}]}]):
             msg = self.test_record.with_user(self.user_employee).message_post(
                 body='<p>Test Answer</p>',
-                message_type='comment', subtype='mt_comment',
+                message_type='comment', subtype_xmlid='mail.mt_comment',
                 partner_ids=[self.partner_1.id],
                 parent_id=parent_msg.id)
 
@@ -177,7 +177,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
 
         new_msg = self.test_record.with_user(self.user_employee).message_post(
             body='<p>Test Answer Bis</p>',
-            message_type='comment', subtype='mt_comment',
+            message_type='comment', subtype_xmlid='mail.mt_comment',
             parent_id=msg.id)
 
         self.assertEqual(new_msg.parent_id.id, parent_msg.id, 'message_post: flatten error')
@@ -193,7 +193,7 @@ class TestMessagePost(TestMailCommon, TestRecipients):
         ]), patch.object(MailTestSimple, 'check_access_rights', return_value=True):
             new_msg = self.test_record.with_user(self.user_portal).message_post(
                 body='<p>Test</p>', subject='Subject',
-                message_type='comment', subtype='mt_comment')
+                message_type='comment', subtype_xmlid='mail.mt_comment')
 
         self.assertEqual(new_msg.sudo().notified_partner_ids, (self.partner_1 | self.user_employee.partner_id))
 
@@ -201,14 +201,14 @@ class TestMessagePost(TestMailCommon, TestRecipients):
         with self.assertRaises(AccessError):
             self.test_record.with_user(self.user_portal).message_post(
                 body='<p>Test</p>', subject='Subject',
-                message_type='comment', subtype='mt_comment')
+                message_type='comment', subtype_xmlid='mail.mt_comment')
 
     @mute_logger('odoo.addons.mail.models.mail_mail', 'odoo.addons.mail.models.mail_thread')
     def test_post_internal(self):
         self.test_record.message_subscribe([self.user_admin.partner_id.id])
         msg = self.test_record.with_user(self.user_employee).message_post(
             body='My Body', subject='My Subject',
-            message_type='comment', subtype='mt_note')
+            message_type='comment', subtype_xmlid='mail.mt_note')
         self.assertEqual(msg.partner_ids, self.env['res.partner'])
         self.assertEqual(msg.notified_partner_ids, self.env['res.partner'])
 
diff --git a/addons/test_mail/tests/test_odoobot.py b/addons/test_mail/tests/test_odoobot.py
index 7766b5244dc..740a0444974 100644
--- a/addons/test_mail/tests/test_odoobot.py
+++ b/addons/test_mail/tests/test_odoobot.py
@@ -22,7 +22,7 @@ class TestOdoobot(TestMailCommon, TestRecipients):
             'attachment_ids': [],
             'message_type': 'comment',
             'partner_ids': [],
-            'subtype': 'mail.mt_comment'
+            'subtype_xmlid': 'mail.mt_comment'
         }
         cls.odoobot_ping_body = '<a href="http://odoo.com/web#model=res.partner&amp;id=%s" class="o_mail_redirect" data-oe-id="%s" data-oe-model="res.partner" target="_blank">@OdooBot</a>' % (cls.odoobot.id, cls.odoobot.id)
         cls.test_record_employe = cls.test_record.with_user(cls.user_employee)
diff --git a/addons/test_mail/tests/test_performance.py b/addons/test_mail/tests/test_performance.py
index b7948c23a4b..cf9852d6454 100644
--- a/addons/test_mail/tests/test_performance.py
+++ b/addons/test_mail/tests/test_performance.py
@@ -331,7 +331,7 @@ class TestMailAPIPerformance(BaseMailPerformance):
         with self.assertQueryCount(__system__=5, emp=6):
             record.message_post(
                 body='<p>Test message_post as log</p>',
-                subtype='mail.mt_note',
+                subtype_xmlid='mail.mt_note',
                 message_type='comment')
 
     @users('__system__', 'emp')
@@ -344,7 +344,7 @@ class TestMailAPIPerformance(BaseMailPerformance):
                 body='<p>Test Post Performances basic</p>',
                 partner_ids=[],
                 message_type='comment',
-                subtype='mail.mt_comment')
+                subtype_xmlid='mail.mt_comment')
 
     @mute_logger('odoo.addons.mail.models.mail_mail', 'odoo.models.unlink')
     @users('__system__', 'emp')
@@ -357,7 +357,7 @@ class TestMailAPIPerformance(BaseMailPerformance):
                 body='<p>Test Post Performances with an email ping</p>',
                 partner_ids=self.customer.ids,
                 message_type='comment',
-                subtype='mail.mt_comment')
+                subtype_xmlid='mail.mt_comment')
 
     @users('__system__', 'emp')
     @warmup
@@ -369,7 +369,7 @@ class TestMailAPIPerformance(BaseMailPerformance):
                 body='<p>Test Post Performances with an inbox ping</p>',
                 partner_ids=self.user_test.partner_id.ids,
                 message_type='comment',
-                subtype='mail.mt_comment')
+                subtype_xmlid='mail.mt_comment')
 
     @mute_logger('odoo.models.unlink')
     @users('__system__', 'emp')
@@ -476,7 +476,7 @@ class TestMailComplexPerformance(BaseMailPerformance):
             record.message_post(
                 body='<p>Test Post Performances</p>',
                 message_type='comment',
-                subtype='mail.mt_comment')
+                subtype_xmlid='mail.mt_comment')
 
         self.assertEqual(record.message_ids[0].body, '<p>Test Post Performances</p>')
         self.assertEqual(record.message_ids[0].notified_partner_ids, self.partners | self.user_portal.partner_id)
@@ -823,7 +823,7 @@ class TestMailHeavyPerformancePost(BaseMailPerformance):
                 body='<p>Test body <img src="cid:cid1"> <img src="cid:cid2"></p>',
                 subject='Test Subject',
                 message_type='notification',
-                subtype=None,
+                subtype_xmlid=None,
                 partner_ids=partner_ids,
                 channel_ids=channel_ids,
                 parent_id=False,
diff --git a/addons/test_mass_mailing/tests/test_mail_channel.py b/addons/test_mass_mailing/tests/test_mail_channel.py
index b8bcd59d908..c5b903ff94d 100644
--- a/addons/test_mass_mailing/tests/test_mail_channel.py
+++ b/addons/test_mass_mailing/tests/test_mail_channel.py
@@ -40,7 +40,7 @@ class TestChannelPartnersNotification(common.TestMailCommon):
         self.test_channel.write({'email_send': True})
         self._join_channel(self.test_channel, self.test_partner)
         with self.mock_mail_gateway():
-            self.test_channel.message_post(body="Test", message_type='comment', subtype='mt_comment')
+            self.test_channel.message_post(body="Test", message_type='comment', subtype_xmlid='mail.mt_comment')
 
         self.assertEqual(len(self._mails), 1, 'Number of mail incorrect. Should be equal to 1.')
         for email in self._mails:
diff --git a/addons/website_blog/models/website_blog.py b/addons/website_blog/models/website_blog.py
index 47bff0f31aa..690d62a799c 100644
--- a/addons/website_blog/models/website_blog.py
+++ b/addons/website_blog/models/website_blog.py
@@ -37,7 +37,7 @@ class Blog(models.Model):
         return res
 
     @api.returns('mail.message', lambda value: value.id)
-    def message_post(self, *, parent_id=False, subtype=None, **kwargs):
+    def message_post(self, *, parent_id=False, subtype_id=False, **kwargs):
         """ Temporary workaround to avoid spam. If someone replies on a channel
         through the 'Presentation Published' email, it should be considered as a
         note as we don't want all channel followers to be notified of this answer. """
@@ -45,10 +45,8 @@ class Blog(models.Model):
         if parent_id:
             parent_message = self.env['mail.message'].sudo().browse(parent_id)
             if parent_message.subtype_id and parent_message.subtype_id == self.env.ref('website_blog.mt_blog_blog_published'):
-                if kwargs.get('subtype_id'):
-                    kwargs['subtype_id'] = False
-                subtype = 'mail.mt_note'
-        return super(Blog, self).message_post(parent_id=parent_id, subtype=subtype, **kwargs)
+                subtype_id = self.env.ref('mail.mt_note').id
+        return super(Blog, self).message_post(parent_id=parent_id, subtype_id=subtype_id, **kwargs)
 
     def all_tags(self, join=False, min_limit=1):
         BlogTag = self.env['blog.tag']
diff --git a/addons/website_blog/tests/test_website_blog_flow.py b/addons/website_blog/tests/test_website_blog_flow.py
index 0bca765d48c..d53bc8f7dc4 100644
--- a/addons/website_blog/tests/test_website_blog_flow.py
+++ b/addons/website_blog/tests/test_website_blog_flow.py
@@ -53,7 +53,7 @@ class TestWebsiteBlogFlow(TestWebsiteBlogCommon):
             body='Armande BlogUser Commented',
             message_type='comment',
             author_id=self.user_employee.partner_id.id,
-            subtype='mt_comment',
+            subtype_xmlid='mail.mt_comment',
         )
         self.assertIn(
             self.user_employee.partner_id, test_blog_post.message_partner_ids,
diff --git a/addons/website_forum/controllers/main.py b/addons/website_forum/controllers/main.py
index d0f47befb7b..31606e41a9a 100644
--- a/addons/website_forum/controllers/main.py
+++ b/addons/website_forum/controllers/main.py
@@ -329,7 +329,7 @@ class WebsiteForum(WebsiteProfile):
             post.with_context(mail_create_nosubscribe=True).message_post(
                 body=body,
                 message_type='comment',
-                subtype='mt_comment')
+                subtype_xmlid='mail.mt_comment')
         return werkzeug.utils.redirect("/forum/%s/question/%s" % (slug(forum), slug(question)))
 
     @http.route('/forum/<model("forum.forum"):forum>/post/<model("forum.post"):post>/toggle_correct', type='json', auth="public", website=True)
diff --git a/addons/website_forum/models/forum.py b/addons/website_forum/models/forum.py
index f3738eb07e2..b21845bfd92 100644
--- a/addons/website_forum/models/forum.py
+++ b/addons/website_forum/models/forum.py
@@ -497,12 +497,12 @@ class Post(models.Model):
         if 'content' in vals or 'name' in vals:
             for post in self:
                 if post.parent_id:
-                    body, subtype = _('Answer Edited'), 'website_forum.mt_answer_edit'
+                    body, subtype_xmlid = _('Answer Edited'), 'website_forum.mt_answer_edit'
                     obj_id = post.parent_id
                 else:
-                    body, subtype = _('Question Edited'), 'website_forum.mt_question_edit'
+                    body, subtype_xmlid = _('Question Edited'), 'website_forum.mt_question_edit'
                     obj_id = post
-                obj_id.message_post(body=body, subtype=subtype)
+                obj_id.message_post(body=body, subtype_xmlid=subtype_xmlid)
         if 'active' in vals:
             answers = self.env['forum.post'].with_context(active_test=False).search([('parent_id', 'in', self.ids)])
             if answers:
@@ -717,7 +717,7 @@ class Post(models.Model):
             'email_from': self_sudo.create_uid.email_formatted,  # use sudo here because of access to res.users model
             'body': tools.html_sanitize(self.content, sanitize_attributes=True, strip_style=True, strip_classes=True),
             'message_type': 'comment',
-            'subtype': 'mail.mt_comment',
+            'subtype_xmlid': 'mail.mt_comment',
             'date': self.create_date,
         }
         new_message = question.with_context(mail_create_nosubscribe=True).message_post(**values)
diff --git a/addons/website_livechat/models/mail_channel.py b/addons/website_livechat/models/mail_channel.py
index 5f3b05b2ccd..6f0ddee0fc7 100644
--- a/addons/website_livechat/models/mail_channel.py
+++ b/addons/website_livechat/models/mail_channel.py
@@ -69,7 +69,7 @@ class MailChannel(models.Model):
                 message = _('has left the conversation.')
             leave_message = '%s %s' % (name, message)
             self.message_post(author_id=self.env.ref('base.user_root').sudo().partner_id.id,
-                              body=leave_message, message_type='comment', subtype='mt_comment')
+                              body=leave_message, message_type='comment', subtype_xmlid='mail.mt_comment')
 
     def message_post(self, **kwargs):
         """Override to mark the visitor as still connected.
diff --git a/addons/website_slides/models/slide_channel.py b/addons/website_slides/models/slide_channel.py
index 77aacea09d9..90fa7898eb9 100644
--- a/addons/website_slides/models/slide_channel.py
+++ b/addons/website_slides/models/slide_channel.py
@@ -398,7 +398,7 @@ class Channel(models.Model):
         return res
 
     @api.returns('mail.message', lambda value: value.id)
-    def message_post(self, *, parent_id=False, subtype=None, **kwargs):
+    def message_post(self, *, parent_id=False, subtype_id=False, **kwargs):
         """ Temporary workaround to avoid spam. If someone replies on a channel
         through the 'Presentation Published' email, it should be considered as a
         note as we don't want all channel followers to be notified of this answer. """
@@ -408,10 +408,8 @@ class Channel(models.Model):
         if parent_id:
             parent_message = self.env['mail.message'].sudo().browse(parent_id)
             if parent_message.subtype_id and parent_message.subtype_id == self.env.ref('website_slides.mt_channel_slide_published'):
-                if kwargs.get('subtype_id'):
-                    kwargs['subtype_id'] = False
-                subtype = 'mail.mt_note'
-        return super(Channel, self).message_post(parent_id=parent_id, subtype=subtype, **kwargs)
+                subtype_id = self.env.ref('mail.mt_note').id
+        return super(Channel, self).message_post(parent_id=parent_id, subtype_id=subtype_id, **kwargs)
 
     # ---------------------------------------------------------
     # Business / Actions
diff --git a/addons/website_slides/models/slide_slide.py b/addons/website_slides/models/slide_slide.py
index 9e0730a1abb..57a40d140af 100644
--- a/addons/website_slides/models/slide_slide.py
+++ b/addons/website_slides/models/slide_slide.py
@@ -483,7 +483,7 @@ class Slide(models.Model):
             slide.channel_id.with_context(mail_create_nosubscribe=True).message_post(
                 subject=subject,
                 body=html_body,
-                subtype='website_slides.mt_channel_slide_published',
+                subtype_xmlid='website_slides.mt_channel_slide_published',
                 email_layout_xmlid='mail.mail_notification_light',
             )
         return True