I have a situation where email delivered to a single namespace needs to be delivered to a user who could be in one of a number of downstream system (but we don't know which one). I was wondering if I could use "Callback Verification" http://en.wikipedia.org/wiki/Callback_verification to achieve this?
Ideally, I'd like to avoid the use of a look up table. To recap, the mail flow would be as follows (In the case where the user exists, send to the appropriate MTA) -> u...@mail.org => Callback Verification on recipient -> MTA hosting 1.mail.org (miss, user does not exist in this namespace) -> MTA hosting 2.mail.org (hit! deliver to u...@2.mail.org) (In the case where the user does not exist, send an NDR) -> u...@mail.org => Callback Verification on recipient -> MTA hosting 1.mail.org (miss, user does not exist in this namespace) -> MTA hosting 2.mail.org (miss, send NDR) Thanks in advance. Sincerely, Adam | Identity Concepts | a: PO Box 451 Hamilton, | Brisbane, QLD 4007, Australia | m:+61 419 637 518 | e: adam_j_brad...@identityconcepts.com.au | im: adam_j_brad...@hotmail.com | skype: adam_j_bradley | w:http://www.identityconcepts.com.au | “I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait till oil and coal run out before we tackle that.” [ Thomas Alva Edison ]
