ESET NOD32 ANTIVIRUS - FOR LINUX-BSD MAIL SERVER User Manual

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4.1. Scanning of inbound e-mail messages
Scanning of the inbound e-mail messages is
performed during the messages transfer between MTA
and MDA. Scheme of this process is in the gure 4-2.
The incoming e-mail is intercepted by nod32mda
module, scanned by main NOD32 daemon ’nod32d’ and
delivered to MAILBOX using original MDA. As shown in
the gure, the virus scanning can be enabled by proper
conguration setting of MTA and nod32mda module. It is
also apparent that the solution is MDA independent.
Note that the majority of mail servers use procmail
or maildrop (MDA). The nod32mda module supports
any MDA. In particular the following MDAs were tested:
procmail, maildrop, deliver and local.mail.
Next sections reviews two dierent procedures of
nod32mda module integration with e-mail messaging
system.
4.1.1. Renaming the original MDA and its replacement by NOD32MDA
This is a simple approach even without a need to make any changes in MTA conguration le. The idea is based on
replacing of original MDA by nod32mda module. Note that the information, on what MDA is used by your MTA, can be
grabbed only by exploring the MTA conguration le. Let‘s assume that the MDA used is for instance /usr/bin/procmail.
You simply rename the original procmail binary le for instance to procmail.real:
mv/usr/bin/procmail/usr/bin/procmail.real
and create the soft link to module nod32mda with the name ‚procmail‘:
ln-s/usr/bin/nod32mda/usr/bin/procmail
In case of RedHat Ready and/or Novell (SuSE) Ready variation of NOD32 for Linux Mail Server the installation path to
the nod32mda is dierent so an appropriate statement is as follows:
ln-s/opt/eset/nod32/bin/nod32mda/usr/bin/procmail
With the above modications, you ensure that all messages originally sent to MDA are primarily catched by
nod32mda module. Still there remains to provide that all messages processed by nod32mda will be sent to the original
MDA ‚procmail‘ binary le (currently named ‚procmail.real‘). To do so, just modify parameter ‚mda_path‘ within section
[mda] of main NOD32 conguration le in the following way:
mda_path=“/usr/bin/procmail.real“
After the modications yet enter
/etc/init.d/nod32d reload
and newly created conguration will be reread by the system.
Note that we have used ‚procmail‘ MDA in this case, but the advantage of the procedure is that it can be repeated
with arbitrary known MDA. Disadvantage of this method, on the other hand, is that after original MDA upgrade your
chapter 4 / Integration with E-mail Messaging System
FILE FILE
FILE
PIPE
PIPE
NOD32D
MTA
NOD32MDA
Mailbox
MDA
MTA
Mailbox
MDA
Figure 4-2. Inbound e-mail messages delivery without
(the left part of the gure) and with (the right part of the
gure) NOD32 scanning.

ESET NOD32 ANTIVIRUS - FOR LINUX-BSD MAIL SERVER Specifications

General

Type	Antivirus Software
Supported Operating Systems	Linux, BSD
Email Scanning	Yes
Real-time Protection	Yes
License	Commercial
Purpose	Mail Server Protection
Antivirus Engine	ESET NOD32
Updates	Automatic updates
Management	Remote Management