This HowTo is more or less ready for use.
Feel free to change it

For any question use the Forum or PM me (BeNe)

aptitude update

aptitude install libaprutil1-dbd-mysql razor libnet-dns-perl libmailtools-perl spamc spamassassin libmail-dkim-perl dkim-filter clamsmtp libtie-cache-perl libdbd-mysql-perl pyzor

groupadd -g 5001 spamd
useradd -u 5001 -g spamd -s /sbin/nologin -d /var/lib/spamassassin spamd
mkdir /var/lib/spamassassin
chown spamd:spamd /var/lib/spamassassin

Change the file like this:

rewrite_header Subject [***** SPAM _SCORE_ *****]
required_score 5.0
#to be able to use _SCORE_ we need report_safe set to 0
#If this option is set to 0, incoming spam is only modified by adding some "X-Spam-" headers and no changes will be made to the body.
report_safe 0

# Enable the Bayes system
use_bayes 1
use_bayes_rules 1

# Enable Bayes auto-learning
bayes_auto_learn 1

# Enable or disable network checks
skip_rbl_checks 0
use_razor2 1
use_dcc 0
use_pyzor 1

Change /etc/postfix/master.cf

# Uncomment the second line below when unsing AMaViS
smtp      inet  n       -       -       -       -       smtpd
#  -o receive_override_options=no_address_mappings

# Uncomment the second line below when unsing AMaViS
smtp      inet  n       -       -       -       -       smtpd
 -o content_filter=spamassassin
 -o receive_override_options=no_address_mappings

Add on the end of the file:

spamassassin unix -     n       n       -       -       pipe
  flags=Rq user=vmail argv=/usr/bin/spamc -u ${user}@${domain} -e /usr/sbin/sendmail -oi -f ${sender} ${recipient}

Add to main.cf

spamassassin_destination_recipient_limit = 1

ToDO: Need more priviliges to create, update…

mysql -h localhost -u root -p
use mysql;
insert into user (Host, User, Password) values('localhost','spamassassin',password("YoUrPaSSworD"));
insert into db (Host, Db, User, Select_priv, Insert_priv, Update_priv, Delete_priv) values('localhost','spamassassin','spamassassin','Y','Y','Y','Y');
create database spamassassin;
flush privileges;
quit;

mysql -u spamassassin -p spamassassin < /usr/share/doc/spamassassin/sql/awl_mysql.sql
mysql -u spamassassin -p spamassassin < /usr/share/doc/spamassassin/sql/userpref_mysql.sql
mysql -u spamassassin -p spamassassin < /usr/share/doc/spamassassin/sql/bayes_mysql.sql

# mysql -u spamassassin -p
use spamassassin;
INSERT INTO userpref (username,preference,value) VALUES ('$GLOBAL','required_hits','5.0');
INSERT INTO userpref (username,preference,value) VALUES ('$GLOBAL','report_safe','1');
INSERT INTO userpref (username,preference,value) VALUES ('$GLOBAL','use_bayes','1');
INSERT INTO userpref (username,preference,value) VALUES ('$GLOBAL','use_dcc','1');
exit;

bayes_store_module      Mail::SpamAssassin::BayesStore::MySQL
bayes_sql_dsn           DBI:mysql:spamassassin:localhost:3306
bayes_sql_username      spamassassin
bayes_sql_password      YoUrPaSSworD

auto_whitelist_factory          Mail::SpamAssassin::SQLBasedAddrList
user_awl_dsn                    DBI:mysql:spamassassin:localhost:3306
user_awl_sql_username           spamassassin
user_awl_sql_password           YoUrPaSSworD

user_scores_dsn                  DBI:mysql:spamassassin:localhost:3306
user_scores_sql_username         spamassassin
user_scores_sql_password         YoUrPaSSworD
user_scores_sql_custom_query     SELECT preference, value FROM _TABLE_ WHERE username = _USERNAME_ OR username = '$GLOBAL' OR username = CONCAT('%',_DOMAIN_) ORDER BY username ASC

# 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.
#
#bayes_sql_override_username vmail

 
# /etc/default/spamassassin
# Duncan Findlay

# WARNING: please read README.spamd before using.
# There may be security risks.

# Change to one to enable spamd
ENABLED=1

# Set new created SAHOME
SAHOME="/var/lib/spamassassin/"

# Options
# See man spamd for possible options. The -d option is automatically added.

# SpamAssassin uses a preforking model, so be careful! You need to
# make sure --max-children is not set to anything higher than 5,
# unless you know what you're doing.

##OPTIONS="--create-prefs --max-children 5 --helper-home-dir"
OPTIONS="-d -q -x --create-prefs --max-children 5 --username spamd --helper-home-dir ${SAHOME} -s ${SAHOME}spamd.log"

# Pid file
# Where should spamd write its PID to file? If you use the -u or
# --username option above, this needs to be writable by that user.
# Otherwise, the init script will not be able to shut spamd down.
##PIDFILE="/var/run/spamd.pid"
PIDFILE="${SAHOME}spamd.pid"

# Set nice level of spamd
#NICE="--nicelevel 15"

# Cronjob
# Set to anything but 0 to enable the cron job to automatically update
# spamassassin's rules on a nightly basis
CRON=0

Please use this just for debug (no daemonize)

spamd -D -q -x --create-prefs --max-children 5 --username spamd --helper-home-dir /var/lib/spamassassin/ -s /var/lib/spamassassin/spamd.log --pidfile=/var/lib/spamassassin/spamd.pid

We use ClamSMTP for AntiVirus

# ------------------------------------------------------------------------------
#                        SAMPLE CLAMSMTPD CONFIG FILE
# ------------------------------------------------------------------------------
# 
# - Comments are a line that starts with a #
# - All the options are found below with their defaults commented out


# The address to send scanned mail to. 
# This option is required unless TransparentProxy is enabled
OutAddress: 10025

# The maximum number of connection allowed at once.
# Be sure that clamd can also handle this many connections
#MaxConnections: 64

# Amount of time (in seconds) to wait on network IO
#TimeOut: 180

# Address to listen on (defaults to all local addresses on port 10025)
Listen: 127.0.0.1:10026

# The address clamd is listening on
ClamAddress: /var/run/clamav/clamd.ctl

# A header to add to all scanned email
#Header: X-AV-Checked: ClamAV using ClamSMTP

# Directory for temporary files
TempDirectory: /var/spool/clamsmtp

# PidFile: location of PID file
PidFile: /var/run/clamsmtp/clamsmtpd.pid

# Whether or not to bounce email (default is to silently drop)
Bounce: on

# Whether or not to keep virus files 
#Quarantine: off

# Enable transparent proxy support 
#TransparentProxy: off

# User to run as
User: clamsmtp

# Virus actions: There's an option to run a script every time a 
# virus is found. Read the man page for clamsmtpd.conf for details.

##VirusAction: /usr/local/bin/clamsmtpvirus.sh

There is no need to enable an ActionScript, but there is one

#!/bin/bash
# !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
#   WARNING WARNING WARNING WARNING WARNING WARNING WARNING
#
#  By using variables passed in from clamsmtpd in FILE
#  manipulation commands without escaping their contents
#  you are opening yourself up to REMOTE COMPROMISE. You
#  have been warned. Do NOT do the following unless you
#  want to be screwed big time:main.inc.php
#
#  mv $EMAIL "$SENDER.eml"
#
##  An attacker can use the above command to compromise your
#  computer. The only variable that is guaranteed safe in
#  this regard is $EMAIL.
#
#  The following script does not escape its variables
#  because it only uses them in safe ways.
#
# !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

# A sample script for virus actions. When testing make sure
# everything can run as the clamav (or relevant) user.

FILE="/var/log/clamsmtpd.log"
DIR="/var/spool/clamsmtp"

exec 1>>$FILE
exec 2>>$FILE

# Add some fun log lines to the log FILE

echo "-------------------------------------------------------"
echo Sender  $SENDER
echo Recipients  $RECIPIENTS
echo Virus  $VIRUS
echo "-------------------------------------------------------"

# Move the virus FILE to another DIRectory
# This only works if Quarantine is enabled
#
#if [ -n "$EMAIL" ]; then
#       mv "$EMAIL" "$DIR"
#fi

#
MAILNAME="$(cat /etc/mailname)"
ADMIN="postmaster@server"
DATEI=$(echo "$DIR/$(ls -ltr $DIR )" | awk '{print $8}' | tail -n 1)
ZEILE=$(grep -n -v -e [0-9] -e [a-z] -e [A-Z] $DIR/$DATEI \
|awk -F: '{print $1}' |head -n1)
#
#Text fuer die Email
MAILTEXT="
Dies ist der Postfix Mailserver von $MAILNAME

Es tut mir leid Ihnen mitteilen zu muessen, dass Ihre Nachricht
gesendet von: $SENDER
gesendet an: $RECIPIENTS
nicht zugestellt werden konnte. Es wurde ein Virus gefunden!

*** VIRUS ***: $VIRUS

Detailierte Emailkopfzeile der Nachricht:

$(head -n $ZEILE $DIR/$DATEI)

postmaster@$MAILNAME

"
#
#Mail verschicken
### Mail an den Absender der Virusmail schicken
echo "$MAILTEXT" | mail -s "Ihre Nachricht an $RECIPIENTS,\
$(date)" $SENDER
### Mail an den eigentlichen Empfänger schicken
echo "$MAILTEXT" | mail -s "Virus Email von $SENDER empfangen,\
$(date)" $RECIPIENTS
### Mail an den Admin senden
echo "$MAILTEXT" | mail -s "Virus Email von $SENDER an $RECIPIENTS empfangen,\
$(date)" $ADMIN

# AV scan filter (used by content_filter)
scan    unix    -       -       n       -       16      smtp
  -o smtp_send_xforward_command=yes

# For injecting mail back into postfix from the filter
127.0.0.1:10025 inet n - n - 16 smtpd
  -o content_filter=
  -o receive_override_options=no_unknown_recipient_checks,no_header_body_checks
  -o smtpd_helo_restrictions=
  -o smtpd_client_restrictions=
  -o smtpd_sender_restrictions=
  -o smtpd_recipient_restrictions=permit_mynetworks,reject
  -o mynetworks_style=host
  -o smtpd_authorized_xforward_hosts=127.0.0.0/8

content_filter = scan:127.0.0.1:10026
receive_override_options = no_address_mappings

cd /var/www/imscp/gui/public/tools/webmail/plugins
wget http://www.tehinterweb.co.uk/roundcube/plugins/sauserprefs.tar.gz
tar -xvzf sauserprefs.tar.gz
chown -R vu2000:www-data sauserprefs

vi /var/www/imscp/gui/public/tools/webmail/plugins/sauserprefs/config.inc.php

Add your MySQL Data to connect to the spamassassin DB

// spamassassin database settings
$rcmail_config['sauserprefs_db_dsnw'] = 'mysql://spamassassin:YoUrPaSSworD@localhost/spamassassin';

vi /var/www/imscp/gui/public/tools/webmail/config/main.inc.php

Add sauserprefs and managesieve

$rcmail_config['plugins'] = array('sauserprefs', 'managesieve');

Here is a learnscript for MarkasJunk2… We need it later as a cronjob.

#!/bin/bash
echo "Learning from virtual i-MSCP users:";
for domain in $(ls -1 /var/mail/virtual/); do
 for user in $(ls -1 /var/mail/virtual/$domain); do
  if [ -d /var/mail/virtual/$domain/$user/.Junk ]; then
   echo " + $user@$domain spam"
   echo -n "   --> "
   sa-learn --spam /var/mail/virtual/$domain/$user/.Junk/{cur,new} -u $user@$domain
   echo " + $user@$domain ham"
   echo -n "   --> "
   sa-learn --ham /var/mail/virtual/$domain/$user/cur -u $user@$domain
  fi
 done
done
echo
echo "Done."

Mark as Junk2 Plugin for RC 0.8.x