User Guide

54 Kaspersky
®
SMTP-Gateway 5.5 for Linux/Unix
DOS attacks aimed at paralyzing your mail server with huge volumes of mail
traffic.
You can find all restriction settings in the [smtpgw.limits] section
of the application configuration file.
You can set the following restrictions:
• Number of objects simultaneously processed by the Receiver, Sender
and the AV modules (the IncomingSessions, OutgoingSessions, and
AntiviralSessions options, respectively).
• Maximum number of message hops (MaximalIncomingHops option).
Set this parameter to avoid looping due to incorrect configuration of the
routing table.
• Limit the maximum size for messages received by the server (Maximal-
IncomingMessageSize option) and the total number of messages
received during one mail session (MaximalIncomingMessagesPer-
Session option).
• Limit the number of recipients of a single message (MaximalIncoming-
RcptsPerMessage option). This parameter prevents spam addressed to
your users).
• Maximum size of a single mail session (MaximalIncomingSessionSize
option).
• Maximum number of simultaneous connections from the same IP address
(or host) that are processed by the Receiver and by the Sender modules
(MaximalIncomingSessionsPerlP and
MaximalOutgoingSessionsPerHost options respectively).
If the mail traffic transferred by your server exceeds the specified limits, we
recommend that you decrease the number of objects simultaneously processed
by the AV module (AntiviralSessions parameter) and the number of hops for a
single message (MaximalIncomingMessageSize option). This increases
application performance and message processing speed.
If your server has a low-speed Internet connection, the following actions are
recommended:
• Decrease the number of objects simultaneously processed by the
Receiver and Sender modules (IncomingSessions and
OutgoingSessions options).
• Decrease the maximum number of incoming messages received during a
single session (MaximalIncomingMessagesPerSession option).