When I tried to send emails with Amazon SES from a droplet, I always get this error in the log:

to=my@email.com, relay=none, delay=592, delays=592/0.07/0/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service error for name=email-smtp.us-east-1.amazonaws.com type=MX: Host not found, try again)

But when I do it from my EC2 instance, it works fine.

The droplet and the EC2 instance have identical postfix settings. I followed instructions on http://docs.aws.amazon.com/ses/latest/DeveloperGuide/postfix.html to the letter.

Any idea? Please advise!

Thanks so much.