diff --git a/addons/microsoft_calendar/models/__init__.py b/addons/microsoft_calendar/models/__init__.py
index 8d933a1a60b..a87bf35b73d 100644
--- a/addons/microsoft_calendar/models/__init__.py
+++ b/addons/microsoft_calendar/models/__init__.py
@@ -6,3 +6,4 @@ from . import microsoft_sync
 from . import calendar
 from . import calendar_recurrence_rule
 from . import res_users
+from . import calendar_attendee
diff --git a/addons/microsoft_calendar/models/calendar_attendee.py b/addons/microsoft_calendar/models/calendar_attendee.py
new file mode 100644
index 00000000000..9a462c38f70
--- /dev/null
+++ b/addons/microsoft_calendar/models/calendar_attendee.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from odoo import models
+
+from odoo.addons.microsoft_calendar.models.microsoft_sync import microsoft_calendar_token
+
+
+class Attendee(models.Model):
+    _name = 'calendar.attendee'
+    _inherit = 'calendar.attendee'
+
+    def _send_mail_to_attendees(self, template_xmlid, force_send=False, ignore_recurrence=False):
+        """ Override the super method
+        If not synced with Microsoft Outlook, let Odoo in charge of sending emails
+        Otherwise, Microsoft Outlook will send them
+        """
+        with microsoft_calendar_token(self.env.user.sudo()) as token:
+            if not token:
+                super()._send_mail_to_attendees(template_xmlid, force_send, ignore_recurrence)