diff --git a/addons/google_gmail/models/google_gmail_mixin.py b/addons/google_gmail/models/google_gmail_mixin.py
index 289a0443fb81f..28ecef919764b 100644
--- a/addons/google_gmail/models/google_gmail_mixin.py
+++ b/addons/google_gmail/models/google_gmail_mixin.py
@@ -144,10 +144,14 @@ def _generate_oauth2_string(self, user, refresh_token):
         :return: The SASL argument for the OAuth2 mechanism.
         """
         self.ensure_one()
+        # token life is around 1 hour, add 5s threshold to gives
+        # time to contact google servers and avoid clock synchronization
+        # problems
+        threshold_seconds = 5
         now_timestamp = int(time.time())
         if not self.google_gmail_access_token \
            or not self.google_gmail_access_token_expiration \
-           or self.google_gmail_access_token_expiration < now_timestamp:
+           or self.google_gmail_access_token_expiration - threshold_seconds < now_timestamp:
 
             access_token, expiration = self._fetch_gmail_access_token(self.google_gmail_refresh_token)
 
diff --git a/addons/google_gmail/tests/__init__.py b/addons/google_gmail/tests/__init__.py
new file mode 100644
index 0000000000000..7a800575a7fe4
--- /dev/null
+++ b/addons/google_gmail/tests/__init__.py
@@ -0,0 +1 @@
+from . import test_google_gmail
diff --git a/addons/google_gmail/tests/test_google_gmail.py b/addons/google_gmail/tests/test_google_gmail.py
new file mode 100644
index 0000000000000..9b8baf00abc2c
--- /dev/null
+++ b/addons/google_gmail/tests/test_google_gmail.py
@@ -0,0 +1,50 @@
+from odoo.tests.common import SavepointCase
+from unittest import mock
+import time
+
+class TestIrMailServer(SavepointCase):
+
+    def test_generate_oauth2_string_token_valid(self):
+        now_timestamp = int(time.time())
+        mail_server = self.env["ir.mail_server"].new(
+            {
+                "google_gmail_access_token": "fake_access_token",
+                "google_gmail_access_token_expiration": now_timestamp + 10,
+            }
+        )
+        oauth2_string = mail_server._generate_oauth2_string("user-account", "refresh-token")
+        
+        self.assertIn("fake_access_token", oauth2_string)
+
+
+    def test_generate_oauth2_string_token_expire_in_less_than_5s(self):
+        now_timestamp = int(time.time())
+        mail_server = self.env["ir.mail_server"].new(
+            {
+                "google_gmail_access_token": "fake_access_token",
+                "google_gmail_access_token_expiration": now_timestamp + 2,
+            }
+        )
+        with mock.patch(
+            "odoo.addons.google_gmail.models.google_gmail_mixin.GoogleGmailMixin._fetch_gmail_access_token",
+            return_value=("new-access-token", now_timestamp + 60*60)
+        ):
+            oauth2_string = mail_server._generate_oauth2_string("user-account", "refresh-token")
+        
+        self.assertIn("new-access-token", oauth2_string)
+
+    def test_generate_oauth2_string_token_expired(self):
+        now_timestamp = int(time.time())
+        mail_server = self.env["ir.mail_server"].new(
+            {
+                "google_gmail_access_token": "fake_access_token",
+                "google_gmail_access_token_expiration": now_timestamp - 2,
+            }
+        )
+        with mock.patch(
+            "odoo.addons.google_gmail.models.google_gmail_mixin.GoogleGmailMixin._fetch_gmail_access_token",
+            return_value=("new-access-token", now_timestamp + 60*60)
+        ):
+            oauth2_string = mail_server._generate_oauth2_string("user-account", "refresh-token")
+        
+        self.assertIn("new-access-token", oauth2_string)
\ No newline at end of file
diff --git a/addons/mail/models/mail_mail.py b/addons/mail/models/mail_mail.py
index 2e32ce22451dd..ec5368a16e701 100644
--- a/addons/mail/models/mail_mail.py
+++ b/addons/mail/models/mail_mail.py
@@ -278,7 +278,12 @@ def send(self, auto_commit=False, raise_exception=False):
                     len(batch_ids), server_id)
             finally:
                 if smtp_session:
-                    smtp_session.quit()
+                    try:
+                        smtp_session.quit()
+                    except smtplib.SMTPServerDisconnected:
+                        _logger.info(
+                            "Ignoring SMTPServerDisconnected while trying to quit non open session"
+                        )
 
     def _send(self, auto_commit=False, raise_exception=False, smtp_session=None):
         IrMailServer = self.env['ir.mail_server']
diff --git a/addons/mail/tests/__init__.py b/addons/mail/tests/__init__.py
index 7287046d6ccac..9bdf6981482d8 100644
--- a/addons/mail/tests/__init__.py
+++ b/addons/mail/tests/__init__.py
@@ -5,3 +5,4 @@
 from . import test_mail_render
 from . import test_res_partner
 from . import test_update_notification
+from . import test_mail_mail
\ No newline at end of file
diff --git a/addons/mail/tests/test_mail_mail.py b/addons/mail/tests/test_mail_mail.py
new file mode 100644
index 0000000000000..07569c623750f
--- /dev/null
+++ b/addons/mail/tests/test_mail_mail.py
@@ -0,0 +1,17 @@
+from odoo.tests import SavepointCase
+from unittest import mock
+import smtplib
+
+
+class MailCase(SavepointCase):
+
+    def test_mail_send_missing_not_connected(self):
+        """This assume while calling self.env['ir.mail_server'].connect() it return
+        an disconnected smtp_session which is a non falsy object value"""
+        
+        not_connected = smtplib.SMTP(local_hostname="fake-hostname.com", port=9999, timeout=1)
+        mail = self.env["mail.mail"].new({})
+        with mock.patch("odoo.addons.base.models.ir_mail_server.IrMailServer.connect", return_value=not_connected):
+            mail.send()
+        # if we get here SMTPServerDisconnected was not raised
+        self.assertEqual(mail.state, "outgoing")
\ No newline at end of file