[sllug-members]: smtp server

[Lonnie Olson]

Knight Walker wrote:
> On Mon, 2006-10-30 at 20:00 -0700, Chris Brown wrote:
>> I agree with all the suggestions made. Just keep in mind that the
>> spamassassin component does not scale well in one machine volume wise. I
>> still strongly recommend it, but it is a resource hog. Give it plenty of
>> RAM and CPU if expecting more than say 50,000 to 100,000 emails a week.
> 
> Speaking of which, anyone know (or have URLs to) tricks to speed up or
> otherwise optimize Spamassassin, or how to cluster it to handle large
> numbers of messages?

My technique for optimizing SA scanning has many different parts.

1. Use spamc/spamd.
Don't call spamassassin to process messages, call spamc.  It starts up
quicker and you can either specify a list of hosts, or a single host
that resolves to several addresses.  spamc is smart enough to fail-over
and do very basic balancing.

When your mail load grows, you can throw more spamd servers at it very
easily.

See `man spamc` and `man spamd`

2. Use SQL for preferences and bayes databases.  This will reduce your
need for mounting /home everywhere, and possibly speeding up preference
lookups.  You also gain the ability to manage preferences for your users
much easier.
http://wiki.apache.org/spamassassin/UsingSQL
http://wiki.apache.org/spamassassin/BetterDocumentation/SqlReadmeBayes

3. Tweak your spamassassin config and components.  Turn off checks you
don't like, and speed up checks you do like.
   a. cache DNSBL lookups
      Many blacklists publish rsync'able zones to be used with rbldnsd
or even BIND itself.
      http://www.surbl.org/rbldnsd-howto.html
   b. speed up DCC checks
      Use dccifd instead of dccproc.  dccproc requires the overhead of
an extra fork on each check.  dccifd listens on a socket for dcc checks.
http://www.dcc-servers.net/dcc/dcc-tree/dccifd.html
If you process more than 100,000 messages a day, you may consider
running your own DCC server that peers with the rest of the DCC servers
in the world.
http://www.rhyolite.com/anti-spam/dcc/
   c. General DNS cache on locahost
      This can help greatly with DNSBL lookups, SPF lookups, etc.
      http://tldp.org/HOWTO/DNS-HOWTO-3.html