Kaspersky Anti-Spam 3.0

If Kaspersky Anti-Spam 3.0 is installed on a mail server which receives incoming mail not from the Internet directly, but through an intermediate relay-server, increase the number of the Received headers by which the sender’s IP-address is checked. Change the following parameter, to increase the number of the received headers, for it go to: "Settings" > "Check Options" > "Number of 'Received' headers to be parsed while retrieving ip address (for use in DNSBL checks)"

If Kaspersky Anti-Spam 3.0 is installed on a mail server which receives all incoming mail directly from the Internet then you do not need to make any changes in the settings.