SES not sending remote emails from server but working from website

Hi,

The most probable cause for your problem is some firewall or equiv blocking access to the SMTP server of SES.

In that case, I'd suggest to use telnet from your server to see if you can establish a TCP session on port 25 with the mail server.

For the HOW-TO, see https://netbeez.net/blog/telnet-to-test-connectivity-to-tcp/

Best

DIdier

It doesn't sound like a networking issue, since you're receiving the 554 error code over SMTP. It isn't clear from the message you quoted if the error is coming from Amazon SES or CPanel's servers, but it is definitely coming from some SMTP protocol implementation.

Did you provide CPanel with the username and password for authenticating to SES in your AWS account? If so, can you see a more specific error text accompanying the numeric error codes? If SES rejects the mail, it would typically explain the reason with messages such as:

• 554 Access denied: User <UserARN> is not authorized to perform ses:SendRawEmail on resource <IdentityARN>
• 554 Message rejected: Email address is not verified. The following identities failed the check in region <region>: <identity0>, <identity1>, <identity2>

One simple problem could be that CPanel would be trying to send the emails with a sender email address that isn't verified in the SES configuration in your account: https://docs.aws.amazon.com/ses/latest/dg/verify-addresses-and-domains.html. That would cause SES to reject the messages with the 554 error you're seeing, despite the authentication credentials being valid.