I just had the following work done by another admin, but he is no longer available and the server has a problem. Postfix rejects all inbound emails with a 554 error, so there is obviously some configuration problem.
This is how things should be setup:
Total of 182 secondary domains, each domain setup with a single catchall account, 4 aliases (abuse@,admin@,nospam@,spam@), and the exact same password. The aliases for all secondary domains forward to the primary domain.
* Only the primary domain will have a unique user/password
Every secondary domain will have the exact same email configuration.
** IMPORTANT **
It is critical that the Postfix configuration supports virtual domains properly, so that if a request is sent from another SMTP to user@domain5, postfix responds as [login to view URL], NOT mail.primary-postfix-domain.
This should have all been setup already but the server is rejecting emails and responds as primaryhostname every time, not the virtual domain receiving the email, so I am not sure exactly what needs to be done to fix it.