Zarafa Bayesian Learning

Zarafa Bayesian learning

This howto enables SpamAssasin Bayesian learning for Zarafa

The DMZS script (LGPL) works over IMAP. It reads the mail from two folders (LearnAsSpam and LearnAsHam) and feeds it to SpamAssasin's sa-learn. This script is implemented here in a way that it makes use of public folders in Zarafa.

Installation

 yum install perl-Mail-IMAPClient --enablerepo=extras
 wget http://www.dmzs.com/tools/files/spam/DMZS-sa-learn.pl
 mv DMZS-sa-learn.pl /usr/bin/

Create a user-account in Zarafa for reading the public spam-folders.

 db method, Replace the <MyPassword> with a proper strong password.
 zarafa-admin -c 'SpamAdmin' -p '<MyPassword>' -f 'Spam Administration Account' -e root@localhost

 unix method, if per user
 db accounts setprop SpamAdmin zarafa enabled
 /etc/e-smith/events/actions/qmail-update-user

Now we'll edit the script and replace the Server, User and Password values. We will also have to replace two folder names throughout the script:

 pico /usr/bin/DMZS-sa-learn.pl

Replace the values so it looks like below, replace <MyPassword> for the password you have chosen in a previous step:

 my $imap = Mail::IMAPClient->new( Server=> '127.0.0.1:8143',
                                   User => 'SpamAdmin',
                                   Password => '<MyPassword>',
                                   Debug => $debug);

Throughout the script (be aware of the quotes):

 replace: 'spam'  ->  with: 'Public folders/LearnAsSpam'
 replace: 'not-spam'  ->  with: 'Public folders/LearnAsHam'
 remove: --showdots

Set proper permissions on the script:

 chmod 555 /usr/bin/DMZS-sa-learn.pl

Create a file for the script to write some temporary output to:

 touch /tmp/salearn

Login to Zarafa with an account that has admin rights and make two new folders LearnAsSpam and LearnAsHam under: Public folder > Public folders. Set the permissions (right-click folder > Properties > Permission-tab) on both these new folders to:

 Spam administration account
 * Folder visible
 * Read items
 * Edit items: all
 * Delete items: all
 
 Everyone (and/or other users/groups you've added at least need:)
 * Folder visible
 * Create items
 * Edit items: none
 * Delete items: none

	Note:
	Dropping mail in the public 'LearnAsHam' folder may pose a privacy problem if permissions are set less restrictive as shown above!

Create a new crontab fragment:

 pico /etc/e-smith/templates/etc/crontab/91_SpamAssasinLearn

Add the following to the template (change the execution times to your own likings -- Wikipedia on Cron):

 # Running the Spamassasin Bayesian SPAM learning script every hour from 8:00 to 22:00 during weekdays
 0 8-22 * * 1-5 root /usr/bin/DMZS-sa-learn.pl

Make the new fragment active by expanding the template:

 expand-template /etc/crontab

Configuration

Spamassassin has to be enabled in the Email Panel

Bayesian learning has to be enabled and configured in SME with

config setprop spamassassin UseBayes 1 
config setprop spamassassin BayesAutoLearnThresholdSpam 4.00 
config setprop spamassassin BayesAutoLearnThresholdNonspam 0.10 
expand-template /etc/mail/spamassassin/local.cf 
sa-learn --sync --dbpath /var/spool/spamd/.spamassassin -u spamd 
chown spamd.spamd /var/spool/spamd/.spamassassin/bayes_* 
chown spamd.spamd /var/spool/spamd/.spamassassin/bayes.mutex 
chmod 640 /var/spool/spamd/.spamassassin/bayes_* 
signal-event email-update

These commands will:

• enable bayesian filter
• 'autolearn' as SPAM any email with a score above 4.00
• 'autolearn' as HAM any email with a score below 0.10

Usage

	Warning:
	All mail dropped in the LearnAsSpam and LearnAsHam folders will be automatically deleted !!

• Move/copy spam messages that are delivered to your Inbox to the public LearnAsSpam folder.
• COPY regular messages that end up in your Junk E-mail folder to the public LearnAsHam folder.

After the messages have been processed they will be deleted to save your valuable space.