[gentoo-server] creating a black hole for load testing mail servers

[Kurt Lieber]

At work, we are load testing a number of different mail servers.  I need to
send large amounts of mail through the boxes as part of this.  To get rid
of the mail, I'd like to have a Gentoo box running exim or another MTA on
the end of the chain that does two very simple things:

* Accepts any and all mail that is sent to it, regardless of domain,
  recipient, etc.
* Delivers all mail to /dev/null

This needs to happen as fast as possible.  Ideally, I'd like to prevent the
mail from ever touching the disk for speed reasons, but if that's not
possible through the MTA, I can accomplish the same thing by putting the
spool on a RAM disk.

Is this easy enough to set up?  Any sample configuration files I can crib
from?

Thanks.

--kurt

P.S. if there's another way of accomplishing the same thing, please let me
know.  It is important, however, that the black hole actually have an SMTP
conversation with the sending server.  I can't just route all traffic to
port 25 to /dev/null.