SpamAssassin provides you with a way to reduce if not completely eliminate
Unsolicited Commercial Email (SPAM) from your incoming email. It can
be invoked by a MDA such as sendmail or postfix, or can be called from
a procmail script, .forward file, etc. It uses a genetic-algorithm
evolved scoring system to identify messages which look spammy, then
adds headers to the message so they can be filtered by the user's mail
reading software. This distribution includes the spamd/spamc components
which create a server that considerably speeds processing of mail.

SpamAssassin also includes support for reporting spam messages
automatically, and/or manually, to collaborative filtering databases such
as Vipul's Razor, DCC or pyzor.
Install perl-Razor-Agent package to get Vipul's Razor support.
Install dcc package to get Distributed Checksum Clearinghouse (DCC) support.
Install pyzor package to get Pyzor support.

To enable spamassassin, if you are receiving mail locally, simply add
this line to your ~/.procmailrc:
INCLUDERC=/etc/mail/spamassassin/spamassassin-default.rc

To filter spam for all users, add that line to /etc/procmailrc
(creating if necessary).

drwxr-xr-x    2 root    root                0 sep 23 06:42 /etc/mail/spamassassin
-rw-r--r--    1 root    root              935 sep 23 06:42 /etc/mail/spamassassin/init.pre
-rw-r--r--    1 root    root              526 sep 23 06:42 /etc/mail/spamassassin/local.cf
-rw-r--r--    1 root    root               62 sep 23 06:42 /etc/mail/spamassassin/spamassassin-default.rc
-rwxr-xr-x    1 root    root            36621 sep 23 06:42 /usr/bin/sa-learn
-rwxr-xr-x    1 root    root            29475 sep 23 06:42 /usr/bin/spamassassin
drwxr-xr-x    2 root    root                0 sep 23 06:42 /usr/share/doc/spamassassin-3.0.0
-rw-r--r--    1 root    root           397268 sep 21 18:06 /usr/share/doc/spamassassin-3.0.0/Changes
-rw-r--r--    1 root    root            13967 sep 13 19:34 /usr/share/doc/spamassassin-3.0.0/INSTALL
-rw-r--r--    1 root    root            11637 sep  9 14:29 /usr/share/doc/spamassassin-3.0.0/README
-rw-r--r--    1 root    root             3295 aoû 27 12:37 /usr/share/doc/spamassassin-3.0.0/TRADEMARK
-rw-r--r--    1 root    root             8288 aoû 27 12:37 /usr/share/doc/spamassassin-3.0.0/USAGE
-rw-r--r--    1 root    root             1604 aoû 27 12:37 /usr/share/doc/spamassassin-3.0.0/procmailrc.example
-rw-r--r--    1 root    root             6494 aoû 27 12:37 /usr/share/doc/spamassassin-3.0.0/sample-nonspam.txt
-rw-r--r--    1 root    root              799 aoû 27 12:37 /usr/share/doc/spamassassin-3.0.0/sample-spam.txt
-rw-r--r--    1 root    root            10598 sep 23 06:42 /usr/share/man/man1/sa-learn.1.bz2
-rw-r--r--    1 root    root             6774 sep 23 06:42 /usr/share/man/man1/spamassassin.1.bz2
drwxr-xr-x    2 root    root                0 sep 23 06:42 /usr/share/spamassassin
-rw-r--r--    1 root    root             6018 sep 23 06:42 /usr/share/spamassassin/10_misc.cf
-rw-r--r--    1 root    root             1605 sep 23 06:42 /usr/share/spamassassin/20_anti_ratware.cf
-rw-r--r--    1 root    root             8198 sep 23 06:42 /usr/share/spamassassin/20_body_tests.cf
-rw-r--r--    1 root    root             1613 sep 23 06:42 /usr/share/spamassassin/20_compensate.cf
-rw-r--r--    1 root    root            12029 sep 23 06:42 /usr/share/spamassassin/20_dnsbl_tests.cf
-rw-r--r--    1 root    root            15700 sep 23 06:42 /usr/share/spamassassin/20_drugs.cf
-rw-r--r--    1 root    root            11268 sep 23 06:42 /usr/share/spamassassin/20_fake_helo_tests.cf
-rw-r--r--    1 root    root            27699 sep 23 06:42 /usr/share/spamassassin/20_head_tests.cf
-rw-r--r--    1 root    root            15487 sep 23 06:42 /usr/share/spamassassin/20_html_tests.cf
-rw-r--r--    1 root    root            10939 sep 23 06:42 /usr/share/spamassassin/20_meta_tests.cf
-rw-r--r--    1 root    root            22099 sep 23 06:42 /usr/share/spamassassin/20_phrases.cf
-rw-r--r--    1 root    root             4966 sep 23 06:42 /usr/share/spamassassin/20_porn.cf
-rw-r--r--    1 root    root            14092 sep 23 06:42 /usr/share/spamassassin/20_ratware.cf
-rw-r--r--    1 root    root             5014 sep 23 06:42 /usr/share/spamassassin/20_uri_tests.cf
-rw-r--r--    1 root    root             2334 sep 23 06:42 /usr/share/spamassassin/23_bayes.cf
-rw-r--r--    1 root    root             9117 sep 23 06:42 /usr/share/spamassassin/25_body_tests_es.cf
-rw-r--r--    1 root    root             2738 sep 23 06:42 /usr/share/spamassassin/25_hashcash.cf
-rw-r--r--    1 root    root             2304 sep 23 06:42 /usr/share/spamassassin/25_spf.cf
-rw-r--r--    1 root    root             2624 sep 23 06:42 /usr/share/spamassassin/25_uribl.cf
-rw-r--r--    1 root    root            52292 sep 23 06:42 /usr/share/spamassassin/30_text_de.cf
-rw-r--r--    1 root    root            40681 sep 23 06:42 /usr/share/spamassassin/30_text_fr.cf
-rw-r--r--    1 root    root            57933 sep 23 06:42 /usr/share/spamassassin/30_text_nl.cf
-rw-r--r--    1 root    root            34802 sep 23 06:42 /usr/share/spamassassin/30_text_pl.cf
-rw-r--r--    1 root    root            29377 sep 23 06:42 /usr/share/spamassassin/50_scores.cf
-rw-r--r--    1 root    root             6887 sep 23 06:42 /usr/share/spamassassin/60_whitelist.cf
-rw-r--r--    1 root    root           101479 sep 23 06:42 /usr/share/spamassassin/languages
-rw-r--r--    1 root    root            18944 sep 23 06:42 /usr/share/spamassassin/triplets.txt
-rw-r--r--    1 root    root             1557 sep 23 06:42 /usr/share/spamassassin/user_prefs.template
drwxrwxrwx    2 root    root                0 sep 23 06:42 /var/spool/spamassassin