On Mon, 25 Feb 2008, Andrew Zbikowski wrote:
> For incoming mail I once had a system wide procmail rule that would
> pipe a copy of every incoming mail to something like bzcat >>
> /mnt/Archive/username-Incoming-Archive.bz2.
>
> When you bunzip2ed the archive you got a mbox mail file. If a user
> needed to go through their archive I just created a decompressed copy
> of the file and put it under ~/mail, and they subscribed to it as they
> would any other IMAP folder.
>
> I never got around for something similar for outgoing mail.

  They were doing the same at my work when I started here.  They really did 
want outgoing, though, so I ended up finding a solution years ago (for 
sendmail, anyway):

http://www.freakout.de/logall.c

  There's a similar solution for exim:

unseen save /var/log/fullmail

  I'm guessing one might be able to hack either solution to work 
per-domain.  Not sure what hacks are possible in postfix; I've never 
tried.

      Jima