4.8 KiB
Store SpamAssassin bayes in SQL
[TOC]
Summary
This article will guide you to configure related components to store SpamAssassin Bayes data in SQL server, and allow webmail users to report spam with one click.
Tested with:
- iRedMail-0.8.0, iRedMail-0.8.7.
- CentOS 6.2 (x86_64)
- SpamAssassin-3.3.1
- Amavisd-new-2.6.6
- MySQL-5.1.61
- Roundcubemail-0.7.2
Notes:
- This article should work with all iRedMail releases. We take iRedMail-0.8.0 for example.
- This article should work with all backends: OpenLDAP, MySQL, MariaDB, PostgreSQL. We take MySQL backend for example.
- This article should work with Amavisd-new-2.6.0 and later versions.
IMPORTANT NOTE:
- The bayesian classifier can only score new messages if it already has 200 known spams and 200 known hams.
- If Spamassassin fails to identify a spam, teach it so it can do better next time. e.g. Mark it as spam in roundcube webmail.
- Read
References
section at the end of this article before asking questions.
Create required SQL database used to store bayes data
We need to create a SQL database and necessary tables to store SpamAssassin bayes data. The RPM package installed on CentOS 6 doesn't ship SQL template for bayes database, so we have to download it from Apache web site. We're running SpamAssassin-3.3.1, so what we need is this SQL template file: http://svn.apache.org/repos/asf/spamassassin/tags/spamassassin_release_3_3_1/sql/bayes_mysql.sql If you're running different version, please find the proper SQL file here: http://svn.apache.org/repos/asf/spamassassin/tags/.
# cd /root/
# wget http://svn.apache.org/repos/asf/spamassassin/tags/spamassassin_release_3_3_1/sql/bayes_mysql.sql
Create MySQL database and import SQL template file:
# mysql -uroot -p
mysql> CREATE DATABASE sa_bayes;
mysql> USE sa_bayes;
mysql> SOURCE /root/bayes_mysql.sql;
Create a new MySQL user (with password sa_user_password
) and grant
permissions. IMPORTANT NOTE: Please replace password sa_user_password
by your own password.
mysql> GRANT SELECT, INSERT, UPDATE, DELETE ON sa_bayes.* TO sa_user@localhost IDENTIFIED BY 'sa_user_password';
mysql> FLUSH PRIVILEGES;
Enable Bayes modules in SpamAssassin
Edit /etc/mail/spamassassin/local.cf
, add (or modify below settings):
use_bayes 1
bayes_auto_learn 1
bayes_auto_expire 1
# Store bayesian data in MySQL
bayes_store_module Mail::SpamAssassin::BayesStore::MySQL
bayes_sql_dsn DBI:mysql:sa_bayes:127.0.0.1:3306
# Store bayesian data in PostgreSQL
#bayes_store_module Mail::SpamAssassin::BayesStore::PgSQL
#bayes_sql_dsn DBI:Pg:sa_bayes:127.0.0.1:5432
bayes_sql_username sa_user
bayes_sql_password sa_user_password
# Override the username used for storing data in the database.
# This could be used to group users together to share bayesian filter data.
# You can also use this config option to trick sa-learn to learn data as a
# specific user.
#
# In iRedMail, SpamAssassin is called by Amavisd, so we must set it to be
# same as Amavisd daemon user:
# - on Linux, it's user `amavis`.
# - on FreeBSD, it's user `vscan`.
# - on OpenBSD, it's user `_vscan`.
bayes_sql_override_username amavis
Make sure SpamAssassin will load bayes modules:
# /etc/init.d/amavisd stop
# amavisd -c /etc/amavisd/amavisd.conf debug 2>&1 | grep -i 'bayes'
May 16 09:59:33 ... SpamAssassin loaded plugins: ..., Bayes, ...
May 16 10:27:38 ... extra modules loaded after daemonizing/chrooting:
Mail/SpamAssassin/BayesStore/MySQL.pm, Mail/SpamAssassin/BayesStore/SQL.pm, ...
Looks fine, now press Ctrl-C
to terminate above command, and start Amavisd
service again normally:
# /etc/init.d/amavisd restart
It is required to initialize the database by learning a message. We use the sample spam email shipped in the RPM package provided by CentOS 6:
# rpm -ql spamassassin | grep 'sample-spam'
/usr/share/doc/spamassassin-3.3.1/sample-spam.txt
# sa-learn --spam --username=vmail /usr/share/doc/spamassassin-3.3.1/sample-spam.txt
Learned tokens from 1 message(s) (1 message(s) examined)
Auto learn spam/ham with Dovecot imap_sieve plugin
Backup your sa_bayes
database
Don't forget to update /var/vmail/backup/backup_mysql.sh
(or
backup_pgsql.sh
if you're running PostgreSQL backend) to backup this newly
created sa_bayes
database. For example:
# Part of file `/var/vmail/backup/backup_mysql.sh`
DATABASES='... sa_bayes'
References
- Bayes Introduction. Please do read section
Things to remember
. - SpamAssassin Bayes Frequently Asked Questions