Protection against spam and phishing

A key feature of Kaspersky Security is filtering out spam from the mail traffic passing through the Microsoft Exchange server. The Anti-Spam module filters incoming mail before messages reach user mailboxes.

Anti-Spam scans the following types of data:

Anti-Spam does not scan the following types of data:

Anti-Spam scans the message header, contents, attachments, design elements, and other message attributes. While performing the scan, Anti-Spam uses linguistic and heuristic algorithms that involve comparing the message being scanned with sample messages, as well as additional cloud services, such as Kaspersky Security Network.

After filtering, Anti-Spam assigns one of the following statuses to messages:

You can choose actions to be taken by the application on messages with a particular status. The following operations are available for selection:

The application supports four sensitivity levels of anti-spam scanning:

By default, the application uses the Low sensitivity level of anti-spam protection. You can increase or decrease the sensitivity level. Depending on the sensitivity level and the spam rating assigned after the scan, a message can be tagged as Spam or Probable spam (see table below).

Threshold values of spam rating at different sensitivity levels of spam scanning

Sensitivity level

Potential spam














In exceptional cases, failures in the Anti-Spam kernel operation may result in significantly increased times of message scanning for spam. In such cases, Anti-Spam temporarily switches to the restricted scan mode in order to prevent message detainment. In this mode, some messages can be skipped without undergoing scanning for spam.

In this Help section

Enabling and disabling anti-spam protection of a server

About anti-phishing scans

Enabling and disabling message scanning for phishing

Configuring spam and phishing scan settings

Configuring additional settings of spam and phishing scans

Configuring an increase in the spam rating of messages

About additional services, features, and anti-spam technologies

Using external anti-spam message scanning services

About lists of allowed and denied email addresses

Creating an Anti-Spam address allowlist

Creating an Anti-Spam address denylist

Address Allowlist Record Parameters window

Address Denylist Record Parameters window

Informing Kaspersky of false alerts returned by Anti-Spam

Improving the accuracy of spam detection on Microsoft Exchange 2013 servers

About scanning outgoing mail for spam and phishing content

Enabling and disabling the scanning of outgoing messages for spam and phishing content

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