Added retry logic if the SMTP connection is disconnected by the server.

homeassistant/components/notify/smtp.py

@@ -140,15 +140,20 @@ class MailNotificationService(BaseNotificationService):
         self.username = username
         self.password = password
         self.recipient = recipient
+        self.tries = 2
 
+        self.connect()
+
+
+    def connect(self):
         self.mail = smtplib.SMTP(self._server, self._port)
         self.mail.ehlo_or_helo_if_needed()
         if self.starttls == 1:
             self.mail.starttls()
             self.mail.ehlo()
-
         self.mail.login(self.username, self.password)
 
+
     def send_message(self, message="", **kwargs):
         """ Send a message to a user. """
 
@@ -160,4 +165,10 @@ class MailNotificationService(BaseNotificationService):
         msg['From'] = self._sender
         msg['X-Mailer'] = 'HomeAssistant'
 
-        self.mail.sendmail(self._sender, self.recipient, msg.as_string())
+        for attempt in range(self.tries):
+            try:
+                self.mail.sendmail(self._sender, self.recipient, msg.as_string())
+                break
+            except smtplib.SMTPException as e:
+                _LOGGER.warning('SMTP Exception sending mail: %s' % e)
+                self.connect()