Filtering Mail Received From External Mailboxes - KAPERSKY ANTI-VIRUS 5.0 - FOR LINUX FREEBSD-OPENBSD MAIL SERVER Administrator's Manual

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2.5. Filtering mail received from
external mailboxes
Nowadays, external mailboxes on servers like www.mail.ru, www.aport.ru,
www.hotmail.com etc. are widely used.
How can infection be prevented when downloading infected messages from such
mailboxes? In fact, this mail is delivered via the POP3 protocol, while Kaspersky
®
Anti-Virus only scans mail traffic that uses the SMTP protocol.
In order to ensure antiviral protection of external mail the following is required:
1. Block port 110 and give users simple access to the external mail and
make the gateway work as a proxy-server for POP3 using the fetchmail
package. This package downloads mail messages from external servers
and sends them to the local SMTP port. This is exactly what we need,
since after their coming to the SMTP port the messages are scanned by
Kaspersky Anti-Virus
Filtering mail from external mailboxes requires a local SMTP
server and a local user account on the computer where the
fetchmail package is installed!
Adjustment of fetchmail is very simple: every user in the directory $HOME
has a file .fetcmailrc, containing at least the following lines:
set postmaster "user"
set bouncemail
set no spambounce
set properties ""
poll mail.that.is.free.ru with proto POP3
user 'remote_user' there with password 'pass12345'
is 'user' here
poll mail2.that.is.free.ru with proto POP3
user 'remote_user2' there with password 'pass123452'
is 'user' here
where:
user is the user's name in the local network.
mail.that.is.free.ru and mail2.that.is.free.ru are names of the hosts from
which we need to collect mail.
remote_user
mail.that.is.free.ru and mail2.that.is.free.ru, respectively.
®
.
and remote_user2
Kaspersky Anti-Virus for Unix Mail Servers
are logins for the servers