Clamassassin as Antivirus Solution with Maildrop, Courier and Postfix


The integration of clamassassin into an existing Courier/Postfix installation is quite simple.

First of all you need to install the needed packages:
apt-get install clamassassin clamav clamav-freshclam clamav-daemon clamav-base
 
Supposing that you use maildrop, you just have to edit the file /etc/courier/maildroprc as follows:
exception {
 xfilter "/usr/bin/clamassassin"
 if (/^X-Virus-Status: Yes/)
 {
  to /dev/null
 }
}
 
E-mails passed to maildrop will so directly be deleted if they're scanned positively for a virus.
Instead of deleting them you may want to move them to a quarantine folder instead:
`[ -d $DEFAULT/.Quarantine ]`
if ( $RETURNCODE == 1 )
{
`maildirmake.courier $DEFAULT/.Quarantine`
}
 
exception {
xfilter "/usr/bin/clamassassin"
if (/^X-Virus-Status: Yes/)
{
to "$DEFAULT/.Quarantine/"
}
}
 
At the beginning of the script we make sure that the quarantine folder exists in your mailbox, then we filter the mail and in case it contains a virus moves it to .Quarantine.
That's it.