diff --git a/addons/microsoft_outlook/models/ir_mail_server.py b/addons/microsoft_outlook/models/ir_mail_server.py
index e988569fd6371..41a5a74671513 100644
--- a/addons/microsoft_outlook/models/ir_mail_server.py
+++ b/addons/microsoft_outlook/models/ir_mail_server.py
@@ -2,10 +2,15 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 import base64
+import smtplib
+import threading
 
-from odoo import _, api, models
+
+from odoo import api, models, tools, _
 from odoo.exceptions import UserError
 
+SMTP_TIMEOUT = 60
+
 
 class IrMailServer(models.Model):
     """Add the Outlook OAuth authentication on the outgoing mail servers."""
@@ -52,11 +57,62 @@ def _onchange_use_microsoft_outlook_service(self):
             self.microsoft_outlook_access_token = False
             self.microsoft_outlook_access_token_expiration = False
 
-    def _smtp_login(self, connection, smtp_user, smtp_password):
-        if len(self) == 1 and self.use_microsoft_outlook_service:
-            auth_string = self._generate_outlook_oauth2_string(smtp_user)
-            oauth_param = base64.b64encode(auth_string.encode()).decode()
-            connection.ehlo()
-            connection.docmd('AUTH', 'XOAUTH2 %s' % oauth_param)
+    def connect(self, host=None, port=None, user=None, password=None,
+                encryption=None, smtp_debug=False, mail_server_id=None):
+        # Do not actually connect while running in test mode
+        if getattr(threading.currentThread(), 'testing', False):
+            return None
+        if not (len(self) == 1 and self.use_microsoft_outlook_service):
+            return super(IrMailServer, self).connect(
+                host, port, user, password, encryption, smtp_debug,
+                mail_server_id)
+        mail_server = None
+        if mail_server_id:
+            mail_server = self.sudo().browse(mail_server_id)
+
+        elif not host:
+            mail_server = self.sudo().search([], order='sequence', limit=1)
+
+        if mail_server:
+            smtp_server = mail_server.smtp_host
+            smtp_port = mail_server.smtp_port
+            smtp_user = mail_server.smtp_user
+            smtp_encryption = mail_server.smtp_encryption
+            smtp_debug = smtp_debug or mail_server.smtp_debug
         else:
-            super()._smtp_login(connection, smtp_user, smtp_password)
+            smtp_server = host or tools.config.get('smtp_server')
+            smtp_port = tools.config.get('smtp_port',
+                                         25) if port is None else port
+            smtp_user = user or tools.config.get('smtp_user')
+            smtp_encryption = encryption
+            if smtp_encryption is None and tools.config.get('smtp_ssl'):
+                smtp_encryption = 'starttls'  # smtp_ssl => STARTTLS as of v7
+
+        if not smtp_server:
+            raise UserError(
+                (_("Missing SMTP Server") + "\n" +
+                 _("Please define at least one SMTP server, "
+                   "or provide the SMTP parameters explicitly.")))
+
+        if smtp_encryption == 'ssl':
+            if 'SMTP_SSL' not in smtplib.__all__:
+                raise UserError(
+                    _("Your Odoo Server does not support SMTP-over-SSL. "
+                      "You could use STARTTLS instead. "
+                      "If SSL is needed, an upgrade to Python 2.6 on the server-side "
+                      "should do the trick."))
+            connection = smtplib.SMTP_SSL(smtp_server, smtp_port,
+                                          timeout=SMTP_TIMEOUT)
+        else:
+            connection = smtplib.SMTP(smtp_server, smtp_port,
+                                      timeout=SMTP_TIMEOUT)
+        connection.set_debuglevel(smtp_debug)
+        if smtp_encryption == 'starttls':
+            connection.starttls()
+
+        auth_string = self._generate_outlook_oauth2_string(smtp_user)
+        oauth_param = base64.b64encode(auth_string.encode()).decode()
+        connection.ehlo()
+        connection.docmd('AUTH', 'XOAUTH2 %s' % oauth_param)
+        return connection
+