On Apr 24, 2008, at 10:22 AM, Harm van Tilborg wrote:
What we do is we have seperate boxes that receive e-mail (6 systems
in total), which are announced as four different MX hosts. They all
do spam (spamassassin) and virus (clam) scanning, and forward e-
mail (if it contains no viruses, and a spam score lower then 15) to
the MTA servers.
If such MX servers (as we call it) fails, there are 5 servers left
to replace this one. So concurrency is quite spread out. However,
MTA servers are all single, we are still looking for a good
solution to this...
Take a look at jms1's qmail pages <http://qmail.jms1.net/>. He has a
setup he refers to as "mailhubs" that I've gone with for my server.
Using his validrcptto patch to qmail, and his qmail-updater scripts,
the real mail server just does POP and customer-SMTP (outbound relay)
email. Multiple mail hubs with just qmail, SpamAssassin and ClamAV
(no POP or IMAP) do the scanning.
With this setup, I currently use a VPS with a single provider. When
the load on that grows too large, I plan to either run a second copy
of the VPS at the same provider, or at another one on a separate
network.
Before I was using the VPS to backup some other servers, it only
needed about 1GB of hard disk space, 512MB of RAM and is processing
about 40,000 emails a day. Scale the RAM and CPU time up (or set up
more servers) to handle more email.
-Tom
