From Qmail-LDAP Wiki

Contents 1 Simscan 2 Installation 3 Configuration 4 Activation

Simscan

Simscan(http://www.inter7.com/?page=simscan) is a program that permits to Qmail enable antivirus (with Clamav in this document) and antispam(SpamAssassin) filters. It works with the ALTQUEUE patch(included in stock qmail-ldap). It's written in C, which deliver fast performance.

Installation

If you use clamav user for clamav, you should add --enable-user=clamav parameter to configure line. Also --enable-attach=y will be very helpful.

cd /usr/local/src/tools
wget http://www.inter7.com/simscan/simscan-1.1.tar.gz
tar xvfz simscan-1.1.tar.gz
cd simscan-1.1
./configure --enable-spam=y --enable-spam-passthru=y  --enable-per-domain --enable-spamc-user=y
make
make install-strip

Configuration

In /var/qmail/control/simcontrol:

:clam=yes,spam=yes,spam_passthru=yes

spam_passthru=yes let spam pass with a warning in subjet. If you want to block it, just put spam_passthru=no

And update with:

/var/qmail/bin/simscanmk

Activation

In /service/smtpd/tcp:

127.:allow,RELAYCLIENT=""
:allow,RBL="",RCPTCHECK="",SMTPAUTH="AUTHREQUIRED",QMAILQUEUE="/var/qmail/bin/simscan"

And refresh the smtpd rules with:

cd /service/smtpd
make

In general you have to put the QMAILQUEUE option for those networks that require antivirus. In this case all but localhost.