Rails Mailer “Net::OpenTimeout: execution expired” Exception on production server only

Question

I am using Ruby MRI 2.0.0 and Rails 3.2.12 on a Ubuntu 12.04 TLS VPS and attempting to setup email notifications in my app. It was working fine a few days ago, but n

Answer 1

If you (or the internet in this case as this question is the first result for this problem) are testing Mailgun, you may get this error if you're using port 25. Change the port to 587 worked, even though their docs/quick links says 25 is ok to use.