Email problem with instance (SES service)

Question

Hello,

we have one instance on AWS, and issue with sending emails (we can receive, but not send emails). All mail configuration is on the instance (Ubuntu, PHP + MySQL, Virtualmin).
What we did:
* In SES services, we got out of the sandbox (we submitted a request and it was approved)
* We have verified the domain and email service (added CNAME records)
* We also created an SMTP user and all rights are OK

The only thing we doubt is that AWS has blocked port 25: https://repost.aws/knowledge-center/ec2-port-25-throttle
Maybe missing  MX record or something third?

How to send emails from the instance or somehow move mail out of the instance and send directly from the AWS SES service (which mail client and settings)?

Thanks.

Accepted Answer

Hey thanks for reaching out! The article you shared about throttling on port 25 is correct as EC2 will throttle port 25 by default, but it looks like you have a config issue before anything else as you are currently not able to send any emails from the instance.

You would need to configure an MTA like postfix to use SES as seen here: https://github.com/awsdocs/amazon-ses-developer-guide/blob/master/doc-source/postfix.md

Once the configuration is done and all is good, I recommend you to follow the steps in the article you shared to lift the restrictions on port 25 to avoid any future throttling.

Answer

Hi there.

The article you shared describes what you need to do to allow using SMTP with port 25. You should do this, however; an easier path might be to use a different port, like 465 or 587. All you need is to configure your application to send the emails using any of those ports. You can find more information about it on the documentation page [Connecting to an Amazon SES SMTP endpoint](https://docs.aws.amazon.com/ses/latest/dg/smtp-connect.html).

I hope this helps.

Email problem with instance (SES service)

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