Over the last night I remodelled our main mail servers to finally move
from a much hacked smail with perl spam filters to an exim based system.
The new system has a number of front ends working to an NFS mail spool
using Dan Bernstein's maildir format for the spool (which makes mail work
over NFS pretty well without locking problems and giving good performance
for POP). Exim is a standard (but development) version - 1.653 - with an
"interesting" configuration which handles *many* domains and has lots of
rewrite stuff enabled, plenty of recipient checking etc.... There is also
a small system filter - currently mostly picking up on excessive recipient
counts. The config was written to make *very* extensive use of db lookups.
The pop side was stolen from qmail (and modified slightly to do logging
and to mark mail read).
Its performing wonderfully. Load averages are well down. The queue
"feels" a reasonable length. The old mail transfered like a dream
(although that was done with a perl script outside of the mailers).
All of this would have been much harder without the extensive help given
by Philip Hazel in providing exim, helping out with suggestions on how to
achieve things, implementing maildir from my initial nags and prototype
code etc. Also help to a number of other people who have contributed
ideas to the mailing list, helped me out on some SPAM rules etc. I owe
you all a debt of gratitude and almost certainly some beer.
[As part of the payback, I really *will* get back to my HOWTO/FAQ document
on SPAM filtering which lapsed a little while back]
Nigel.
--
[ Nigel.Metheringham@??? - Systems Software Engineer ]
[ Tel : +44 113 251 6012 Fax : +44 113 224 0003 ]
[ Friends don't let friends use sendmail! ]
