Installation manual

19
5.5. Alternative methods of content ltering
5.5.1. Scanning e-mail messages using AMaViS
AMaViS - A Mail Virus Scanner is a tool that interfaces your MTA and several anti-virus scanners.
It supports various MTAs and comes in three branches: amavis, amavisd and amavisd-new.
Amavis cooperates with ESET Mail Security by using esets_cli. Yet before we go into detailed
explanation of the Amavis congurations, we would like to discuss the impact of the method on
the ESET Mail Security functionality.
First, note that Amavis does not allow modication of the scanned e-mail messages. So no
infected e-mail attachments can be cleaned nor deleted by ESETS. Second consequence is that
no ESETS footnote with log and status dependent header elds will be written into the e-mail.
Next, amavis doesn’t provide mail sender/recipient, so no user specic congurations can be
used, too. Advanced mail handling (accept, defer, discard, reject) is also limited for esets_cli.
Lastly, it scans les and thus cannot use ESETS anti-spam engine.
Taking into account these drawbacks, this conguration is usable if only the above discussed
features of the product are not necessary for the user.
5.5.1.1. amavis
Conguration of Amavis is performed during the Amavis installation. After unpacking the
sourceamavis-0.x.y.tgz,createtheleamavis/av/esets_cliwiththiscontents:
#
# ESET Software ESETS Command Line Interface
#
if ($esets_cli) {
do_log(2,”Using $esets_cli”);
chop($output = `$esets_cli --subdir $TEMPDIR/parts`);
$errval = retcode($?);
do_log(2,$output);
if ($errval == 0) {
$scanner_errors = 0;
} elsif ($errval == 1 || $errval == 2 || $errval == 3) {
$scanner_errors = 0;
@virusname = ($output =~ /virus=”([^”]+)”/g);
do_virus();
} else {
do_log(0,”Virus scanner failure: $esets_cli (error code: $errval)”);
}
}
Note that the above script accepts the email only in case it is accepted in esets_cli’s Handle
Object Policy. In any other case, the mail is blocked. If it a virus was found, it’s name is extracted
from the output.
Next, if you are using the Linux RSR package, you have to update your PATH environment
variable with this command:
export PATH=”$PATH:/opt/eset/esets/bin”
For successful installation you may need to install additional software like arc, unarj, unrar,