Starting with the Praetor v2.1 release of April 2005, CMS no longer recommends that you use SMTP protocol level DNS Blacklist Filtering. Instead, this filtering will be performed at the message rule level. The reason for this is the growing frequency that this technique comes under a denial-of-service attack by spammers who have changed their tactics. For more information on this, click here.
Thus by default this node does not appear in the left pane. It will only appear if you have contacted CMS Support to re-enable this technique.
Praetor records SMTP protocol filter events into a separate container from the normal message events. Typically these will be for events when a message is refused by Praetor, such as the case for messages originating from a DNS blackhole listed mail server.
Each unsuccessful attempt by any sending mail server that attempts to send a message to Praetor is shown on a line that provides:
Date and time of the failed attempt
Event source (type of Praetor filter that refused the message)
Connecting IP address of the sending mail server, and
Any additional information, such as textual from the DNSBL for listing the IP in its blackhole list