SA is processing messages slowly

[ed]

For the past 2 weeks we've been trying to get our new mail server, with Spam Assassin up and running.  I've read all the FAQs and help files and am posting here as a last resort.    We're running 1 gig of memory with a P4 2.4 Prescott processor on Fedora Core 2 with SpamAssassin version 2.63.  We're using SPAMD being called from an init script with /usr/bin/spamd -o -f   The options for spamd are: SPAMDOPTIONS="-d -c -a -m5 -H".   We've been having a problem with email files being processed very slowly by SA (averaging between 20 - 30 sec per message to process).  I had been running several rules until today.  After removing all add on rules, SpamAssassin picked up speed considerably.  It now process an email message in about 1 to 2 seconds.  But at this point we only have a handful of boxes active.    I have three questions that I need help finding the answers for:   1.)  What hardware is recommended to run SquirrelMail with Spam Assassin for about 1000 users.  We have an old domain and receive about 50,000 to 75,000 emails a day.   2.)  How many and which "add on rules" are recommended.  If I start adding them one by one, are there some "must have rules" that I should start with first?   3.)  Any suggestions on how to keep the memory usage down.  Sometimes if SA is processing 5 emails at the same time for more than 10 seconds, the memory usages climbs to almost 100%.   Any help or suggestions are greatly appreciated. Local.cf and procmailrc files are listed below for further info.   Thanks,   Ed *** The spamasassin local.cf file: required_hits 5.0 rewrite_subject 1 subject_tag [SPAM] *** The /etc/procmailrc file: DROPPRIVS=yes :0fw: * < 200000 | /usr/bin/spamassassin :0fw: * ! ^X-Spam-Level:.* * < 200000 | /usr/bin/spamassassin :0: * ^X-Spam-Status: Yes $HOME/mail/mail/Spam