Amazon EC2/SES SMTP Timeout

Question

I have an issue when trying to send emails from my EC2 instance using SMTP to SES. For some reason I am getting sporadic timeout issues, where I can no longer contact the S

Answer 1

If you're running a Django app and suspect Steffen's answer might be the cause - here is a quick litmus test:

In [1]: from django.core.mail.backends.smtp import EmailBackend
In [2]: from django.core.mail import EmailMultiAlternatives
In [3]: message = EmailMultiAlternatives(
   ...:     subject='testing the rate limit',
   ...:     body='this is a test',
   ...:     to=['your+email@example.com'],
   ...:     from_email='from@example.com',
   ...: )
In [4]: backend_587 = EmailBackend(port=587)
In [5]: backend_25 = EmailBackend(port=25)
In [6]: backend_587.send_messages([message])
Out[6]: 1
In [7]: backend_25.send_messages([message])  # hangs for a long time. Might even timeout

Sending the email from port 25 should hang. Sending the email from 587 should send quickly.