SMTP timeouts on Amazon AWS EC2

Amazon AWS EC2 enforces traffic throttling on SMTP causing intermittent timeouts when sending email.


Sending emails with a service like Mandrill or through a normal SMTP server from your Amazon AWS EC2 instances can result in intermittent timeouts.

This is because of a traffic throttling policy on the AWS side to prevent spamming from their servers.


You have the following options:

  1. Use a different port other than 25.
  2. If using Mandrill, use their RESTful API, instead of standard SMTP. This might not be very straight forward as the Mandrill gem is not a drop-in replacement.
  3. Use another service like Postmark where they have a drop-in gem which uses their RESTful API.


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