User Guide

Kaspersky Anti-Spam Operation and Filtering Philosophy 25
data. The linguistic laboratory of Ashmanov & Partners JSC is constantly
improving and updating this database, therefore it is necessary to download the
database updates regularly in order to provide effective spam detection and
processing.
The updates are downloaded via the Internet by the updater script. We strongly
recommend that you include this script into crontab. It is recommended to
schedule it to start at least every hour.
By default the filter data updates are downloaded from
ftp://downloads1.kaspersky-labs.com/sfupdates
; if necessary an alternative
download location may be used.
The update can be either incremental (adding new entries to the database) or
complete (complete replacement of the old database with a new version).
Selection and downloading of the updates, content filtering database and the
filtering service restart are performed automatically.
For more details on the content filtering database updates see Chapter 6,
page 89.
4.3. Filtering philosophy
Processing of an e-mail message is provided by applying filtering rules to such
message.
Each filtering rule consists of an unordered set of conditions and an ordered set
of actions:
• processing of an e-mail message starts with analysis; checking whether
the conditions described in a certain rule are met;
• if at least one condition has not been met, processing of a message by
this rule will be stopped and no actions will be performed;
• if all conditions have been met, then actions defined by this rule will be
applied to this message in the order prescribed by the rule.
Filtering rules grouped into filter profiles. There are two types of filter profiles:
• Common profiles – for all messages, irrespective of the particular
recipient.
• Personal profiles – for messages sent to a certain recipients.