[FIX] backport _smtp_login as well

odoo/addons/base/ir/ir_mail_server.py

@@ -191,6 +191,9 @@ def connect(self, host=None, port=None, user=None, password=None, encryption=Non
         elif not host:
             mail_server = self.sudo().search([], order='sequence', limit=1)
 
+        if not mail_server:
+            mail_server = self.env['ir.mail_server']
+
         if mail_server:
             smtp_server = mail_server.smtp_host
             smtp_port = mail_server.smtp_port
@@ -241,9 +244,19 @@ def connect(self, host=None, port=None, user=None, password=None, encryption=Non
             # See also bug #597143 and python issue #5285
             smtp_user = pycompat.to_native(ustr(smtp_user))
             smtp_password = pycompat.to_native(ustr(smtp_password))
-            connection.login(smtp_user, smtp_password)
+            mail_server._smtp_login(connection, smtp_user, smtp_password)
         return connection
 
+    def _smtp_login(self, connection, smtp_user, smtp_password):
+        """Authenticate the SMTP connection.
+        Can be overridden in other module for different authentication methods.Can be
+        called on the model itself or on a singleton.
+        :param connection: The SMTP connection to authenticate
+        :param smtp_user: The user to used for the authentication
+        :param smtp_password: The password to used for the authentication
+        """
+        connection.login(smtp_user, smtp_password)
+
     def build_email(self, email_from, email_to, subject, body, email_cc=None, email_bcc=None, reply_to=False,
                     attachments=None, message_id=None, references=None, object_id=False, subtype='plain', headers=None,
                     body_alternative=None, subtype_alternative='plain'):