Sending Duplicate Messages with Postfix
We have a system of three boxes that handle mail in different ways. The first is our MX record and handles all incoming mail from the outside. It forwards the mail to our production mail server (the one people have mailboxes on), and performs spam checking, etc. The last box is our new server we are putting into production this weekend (along with a migration from mbox to maildir).
The problem I haven't been able to solve is how to get a copy of the message sent from our MX to both of the destination servers. That way we can always revert to mbox if something begins to look like it's going wrong.
I thought about using transport maps to set our domain to forward from the gateway to both machines, but it doesn't seem transport maps were designed for this purpose. Aliases weren't much of a lead either, and using the bcc option would just plop all the mail in one account on the system (something we really don't want to have to deal with).
I'm just throwing this out there to hopefully get some suggestions or guidance, and thanks in advance to everyone who replies.
If you need more information to help out I'm more than willing to share. Just let me know.