So Ive thought of a way to accomplish my goal with the use of our public mail systems (I work for a ISP). Im thinking about removing my subdomain completely and creating all my mail accounts as email@example.com
, which is the same domain our customers use. Then I can modify my MX records to include my new server in the MX look up. The issue I foresee is the way things have been set up for this system if mail comes in for a customer and for some gawd awful reason the MX servers are busy it will attempt to contact my server being last on the mx record, see that the mailbox does not exist and then bounce the email destined for a customer back to the sender with a "no mailbox by that name" error.
My solution would be to specify a MX transport that says this specified email will be sent directly to this server. Seems like this should work right?
Well the public mail system is built on Qmail and I cannot find any documentation on how to do this or if its even possible. So are there any Qmail users out there that might be able to point me in the right direction?