sending a copy of all inbound messages to two MTAs

[Dhawal Doshy]

Andrew MacLachlan wrote:
> This is a strange request, and I suspect that it's probably a PostFix question:
> can a copy of each inbound message be sent to an alternate MTA?
> This is so a new mailserver can be tested with real inbound mail flows...

This is not a strange request, actually an often asked question.. the 
answer for postfix is using the always_bcc OR recipient_bcc_maps 
configuration parameter..

http://www.postfix.org/postconf.5.html#always_bcc
http://www.postfix.org/postconf.5.html#recipient_bcc_maps

Be careful though, since if a mail to the BCC address bounces it will be 
bounced to the sender.