Issue Recipient address rejected: Server configuration problem

[ValentinoG]

Hi there, hope you're doing fine.

Ubuntu 16.04.6 LTS, latest version of Plesk I'm seeing a lot of these errors "Recipient address rejected: Server configuration problem".

It seems to hit email messages for alias domain > main domain. Any idea?

Cheers

 

[Monty]

Check your maillog (/var/log/mail.log) and syslog (/var/log/syslog), there you will see more information about what happens