Administrator's Guide - Kerio Software Archive

Chapter 16 Antispam control of the SMTP server• Content — insert info@offer.com• Add score to the message — set a negative value that will decrease the total score. Youcan also use the Treat the message as non-spam (overrides the SpamAssassin score)option.If the message was rejected by a custom spam ruleThe settings are applied only to custom rules where the Treat the message as spam and rejectit option is set:Block the message and do not deliver it to the recipientMessage will be discarded without notification. This action is not performed if the rulefilters the From and To items (for details, see above).Send bounce message to the senderThe server returns the sender a DNS message informing that the email message cannotbe delivered.It is not recommended to use this option since most of spam message use false senderaddresses. This implies that the denial message cannot be delivered (the address to whichthe DNS message is sent might not exist). Messages informing about denial of the originalmessages are then waiting in a queue where there must be physically removed, otherwise,the server attempts to send them every 30 minutes and discards the messages after twoor three days.Forward the message to quarantine addressThe address to which messages will be forwarded and where administrator or anotherauthorized person can check whether there are or there are not legitimate messagesincluded in the spam. Using this option is recommended since it helps you avoid losingof non-spam email without any notification.16.4 SpamAssassinTo face spam, Kerio MailServer uses SpamAssassin, a famous antispam filter. SpamAssassinconsists of several testing methods:• filter based on statistical evaluation of message content• Bayesian filter• SURBL (Spam URI Realtime Blocklist) — this method tests links to websites possibly includedinside email against special online databases.Note: For easier solution of problems regarding SpamAssassin that might arise, enable theSpamAssassin Processing option in the Debug log settings. To read more on the Debug log, seechapter 22.8.182