Amazon SES SMTP Connection timed out

  • When you are sending a test mail as sudo /usr/sbin/sendmail -f [email protected] [email protected], the mail is handed over to the sendmail running on your instance.
  • when sendmail tried to deliver the mail to the SMART_HOST which is email-smtp.us-east-1.amazonaws.com, it wasnt able to connect to email-smtp.us-east-1.amazonaws.com and so the email was placed in the deferred queue for retrying later.

So the problem is that your sendmail instance wasnt able to talk to email-smtp.us-east-1.amazonaws.com.

  • Is there any network issue in your instance?
  • Also the document says that you need to fill Request to Remove Email Sending Limitations to remove some restrictions on port 25

I was having trouble with the timeout as well. I didn't have any vpc subnet routing as thiyagu114 said was his issue, and none of clement's suggestions helped.

Found this on the Amazon info:

Important Elastic Compute Cloud (EC2) throttles email traffic over port 25 by default. To avoid timeouts when sending email through the SMTP endpoint from EC2, use a different port (587 or 2587) or fill out a Request to Remove Email Sending Limitations to remove the throttle.

So switching from port 25 to 587 fixed the timeout issue for me.