There has been a similar thread in the past - Monitor Outgoing Email http://discussion.dreamhost.com/showflat.pl?Cat=&Board=forum_troubleshooting&Number=5089&page=&view=&sb=&o=&vc=1
But this isn't quite the same.
What I am trying to do is capture all email sent through a specific user account in order to back it up.
My final goal is to have a real time backup of my email on an independant sever (such as a gmail account). Incomming email is simple enough, but outgoing posses a problem.
I always use IMAP or webmail, so I could resort to a complicated crontab solution, but that wouldn't be real time.
What I envision is a server-side filter that forces all emails to be BCCed to a third email address, adding a custom header so I can filter them out as "sent" mail on the other end. (think procmail for outgoing mail)
--Note the potentail abuse\legality concerns of this feature is more or less the same as the previos thread. No need to duplicate that conversation here.