I've configured my mail server using the HOWTO Virtual Users And Domains With Postfix, Courier And MySQL (Debian Etch) and am having issues with the transport table.
For one of my domains (let's say example.org), I have in the transport table:
example.org smtp:[18.104.22.168] where 22.214.171.124 is the IP address of the other mail server I want all example.org mail to go to. Attemption to email firstname.lastname@example.org
gets a bounce:
550 5.1.1 <email@example.com>: Recipient address rejected: User unknown in virtual mailbox table (in reply to RCPT TO command)
I setup example.org in the domains and transport tables.
I'd like to keep my Postfix server as the MX for example.org but if I can't get this working, I may have to just point the MX record directly to the other mail server.