Spam and Virus Protection

Allow Null Sender
Enable null sender ('MAIL FROM:<>') messages to be accepted by AfterLogic XMail Server.
Check Sender's Domain
Enable validation of the sender domain ('MAIL FROM:<...@xxx>') by looking up DNS/MX entries.
Enable Bayes filter
Enable/disable Bayes spam filtering module. Enabling this option makes sense only in case if you use WebMail Pro integrated with AfterLogic XMail Server as the spam filter needs to be trained via special buttons (Spam / Not Spam) available in WebMail Pro.
Enable antivirus
This checkbox enables antivirus protection during mail-processing. This option uses external antivirus software which should be installed in the system.
It's recommended to review the documentation page.
SMTP Response for IP Banned Spammers
Sets the message that must be sent to the SMTP client when the client IP is listed inside the file SPAMMER.TAB.