Administrator's Guide - Kerio Software Archive

16.7 Recommended configuration of antispam testsDo not apply delay for connections from...Spam repellent settings apply to all incoming SMTP communication events, i.e. also tomessages from local network, backup servers, etc. It is therefore recommended to add alltrustful IP addresses and networks to this IP address group, so that the communicationis not blocked, if the messages are apparently non-spam.Report the spam attack to security logCheck this option to record all recognized spam attacks to the Security log (for moreinformation, see chapter 22.4).If many emails go through Kerio MailServer, there are usually also many spam attackattempts, which can cause security log overflow. In such case, disable this setting.Note: The settings in this tab apply only to the unsecured SMTP communication. The spamdistributing programs do not use the secured SMTP protocol for communication.16.7 Recommended configuration of antispam testsThis section is helpful for anyone who is not sure about proper configuration of antispamfilters. The example describes optimal settings of scores for individual types of antispamtests. Notice that almost never the message blocking is not preferred to increasing of spamscore:Spam Rating tabThe essential setting is configuration of the Spam Rating tab (for details, see section 16.1). Itis recommended to leave most of the settings as predefined by default:1. Make sure that the Enable Spam Filter Rating option is enabled. If the option is inactive,enable it.This option makes the filter consider and apply results of individual evaluations (spamscores).2. Make sure that the Enable rating of messages sent from trustworthy relay agents defined inSMTP relay options option is inactive (unless you wish to check even messages sent fromtrustworthy addresses).3. Follow these instructions to set resolution of the spam filter scale:• Tag score — set the value to 5 points.• Block score — set this value to 9.9 points. This will ensure that only “hundred-percent”spam messages are discarded by the server since users are not even notified that suchmessages would have been blocked (unless at least one of the Send bounce message tothe sender or Forward the message to quarantine address options are enabled).Note: If you do not wish to block any messages no matter what the score is, set thevalue to 10.0 points. This disables blocking of messages and keeps active only thefeature of marking as spam.189