If you're checking through your mail logs, or you catch a bounced e-mail with "554 relay access denied" in the bounce, the issue can be related to a few different things:
If your server bounces with this message when people send e-mail to you:
- Check to make sure that your mail server is configured to receive mail for your domain
- Postfix: /etc/postfix/mydomains (on some systems)
- Sendmail: /etc/mail/local-host-names
- Qmail: /var/qmail/control/rcpthosts
- Verify that your MX records are pointing to your server, and not someone else's (very important during server migrations)
- If you recently made changes in Postfix, make sure to run
postmapon your domains file and runpostfix reload
If you get this message when you try to send e-mail to other people through your server:
- Enable SMTP authentication in your e-mail client
- If SMTP authentication is on in your client, check your server's authentication daemons to be sure they're operating properly
