Improved connection clean-up for SMTP backend.

django/core/mail/backends/smtp.py

@@ -130,10 +130,12 @@ class EmailBackend(BaseEmailBackend):
                 # Trying to send would be pointless.
                 return 0
             num_sent = 0
+            try:
                 for message in email_messages:
                     sent = self._send(message)
                     if sent:
                         num_sent += 1
+            finally:
                 if new_conn_created:
                     self.close()
         return num_sent