13.8  Monitoring of spam filter's functionality and efficiency

Kerio MailServer includes several options of how to monitor spam filter's functionality. Standard tools available in the Kerio Administration Console are sufficient for this purpose:

Spam Filter statistics

Kerio MailServer maintain spam filter's statistics. The statistics can be found in the Status → Statistics section (refer to chapter 24.6  Statistics).

Spam filter's statistics enable find out the proportion of ham (legitimate email) and spam coming in Kerio MailServer. The statistics help you recognize whether individual antispam methods are set properly. It is apparent from the facts whether too much spam leaks in user mailboxes and whether too many legitimate messages are marked as spam.

The statistics covers the following items:

Spam Filter statistics

Figure 13.11. Spam Filter statistics


Messages checked

Total number of all messages that have passed through the antispam filter (messages sent form whitelist domains, for example, are not counted since they are not tested).

Spams detected (tagged)

All messages detected and tagged as spam.

Spams detected (rejected)

All messages blocked by the spam filter.

Messages marked by users as spam

All messages considered by the filter as not spam which were later marked as spam by users (manually, by clicking on Spam or by moving it to the Spam folder).

Messages marked by users as not spam

Legitimate messages detected by the antispam filter improperly as spam— so called “false positives”.

Graphical overviews

Kerio MailServer also uses traffic charts to trace certain values regarding spam email. There are several spam-related traffic charts which can be found in the Status → Traffic Charts section of the Kerio Administration Console (see chapter 24.5  Traffic Charts).

The following graphs focus on spam:

Connections/Rejected SMTP

The chart displays number of attempts of SMTP connection were rejected by the Spam repellent tool in certain time period.

Messages/Spam

With time dependence, the chart displays how large amount of spam is delivered to Kerio MailServer and when.

Logs

Problems that occur regarding the antispam filter might be solved with help of Kerio MailServer's logs. In detail, logs are focused in chapter 25  Logs.

The following logs might be helpful:

Spam

All messages marked as spam are recorded in this log (for details, see chapter 25.8  Spam).

Debug log

Logging of particular information can be performed by this special log. Spam issues may be worked out by using of the following information:

  • Spam Filter — the option logs spam rating of each message which passed through the Kerio MailServer's antispam filter.

  • SPF Record Lookup — the option gathers information of SPF queries sent to SMTP servers. It can be used for solving problems with SPF check.

  • SpamAssassin Processing — the option enables tracing of processes occurred during SpamAssassin antispam tests.

To learn where and how to set logging of particular information in the Debug log, refer to chapter 25.9  Debug log.