I have postfix running on a dedicated mail server connected to mail.example.com. I want to use it to send/receive mail from example.com only.
I have everything setup and working as desired. Mails directed to @example.com come through to postfix on mail.example.com and are sent to the correct users, etc. Everything is good.
What I want to do now is to disable the ability to mail users at their "mail.example.com" addresses. If you attempt to mail firstname.lastname@example.org, I want a bounce message sent.
I tried editing the my_destination values by removing all references to "mail.example.com" there - and it works - mail sent to those addresses are no longer delivered, and the @example.com version still works, but this isn't triggering bounce replies upon mailing. Hopefully I'm not creating more problems by doing that...
Is it possible to set postfix up the way I'd like?