HOWTO install SpamAssassin on Red Hat Linux 7.3
===============================================
by Thomas Chung <tchung@openwebmail.org>
Last Updated: 2003-05-13

1. install following rpm packages

   perl-Mail-SpamAssassin-2.53-1.7.3.i386.rpm
   spamassassin-2.53-1.7.3.i386.rpm
   spamassassin-tools-2.53-1.7.3.i386.rpm

2. create a global spamassassin config file at
   /etc/mail/spamassassin/local.cf

   use SpamAssassin Configuration Generator at
   http://www.yrex.com/spam/spamconfig.php

   make sure to choose: Rewrite Subjects using text "*****SPAM*****"

3. start spamassassin service

   service spamassassin start

4. switch to a user (su - user) then create an individual procmailrc config file 
   instead of global for security concern at
   $HOME/.procmailrc

   type following:

# filter all incoming mail through SpamAssassin and tags probable spam with a unique header
:0fw: spamassassin.lock
| /usr/bin/spamassassin


5. to see spamassassin score using spamd client - spamc:

$spamc -R < /usr/share/doc/spamassassin-2.53/sample-nonspam.txt
-6.3/5.0
PGP_SIGNATURE      (-6.3 points) Contains a PGP-signed message
note: -6.3 is way low to be spam than required hits score 5.0
   
$spamc -R < /usr/share/doc/spamassassin-2.53/sample-spam.txt
7.4/5.0
NO_REAL_NAME       (0.7 points)  From: does not include a real name
INVALID_DATE       (0.6 points)  Invalid Date: header (not RFC 2822)
UNDISC_RECIPS      (1.4 points)  Valid-looking To "undisclosed-recipients"
HOME_EMPLOYMENT    (1.5 points)  BODY: Information on how to work at home (2)
DRASTIC_REDUCED    (1.5 points)  BODY: Drastically Reduced
REMOVE_SUBJ        (0.8 points)  BODY: List removal information
ONCE_IN_LIFETIME   (0.7 points)  BODY: Once in a lifetime, apparently
DATE_IN_PAST_12_24 (0.2 points)  Date: is 12 to 24 hours before Received: date
INVALID_MSGID      (0.4 points)  Message-Id is not valid, according to RFC 2822
AWL                (-0.4 points) AWL: Auto-whitelist adjustment
note: 7.4 is high enough to be spam than required hits score 5.0

6. to test spamassassin by sending a sample spam email from a user to a user

   mail -s test user@domain.com < /usr/share/doc/spamassassin-2.53/sample-spam.txt

7. check the mail from the user account and look for subject as
   
   *****SPAM***** test


ps. To make spam scanner to more sensitive, decrese the number for required_hits in 
    /etc/mail/spamassassin/local.cf from 5.0 to 4.0 for exmaple
    and make sure to restart spamassassin service after changing config file