Mac OS X Lion Server For Dummies®

Blocking Spam and Other Nasty Bits

Lion Server is integrated with several types of filtering software to keep spam and viruses from reaching users. It uses the open source spam-blocking software called SpamAssassin, which does a statistical analysis of incoming e-mail to determine whether it's probable spam. It also supports the blacklisting of certain e-mail servers, rejecting e-mail from known spammers. For this, Lion Server communicates with servers of the Spamhaus Project, an international not-for-profit organization that collects spam blacklist data. Lion Server also includes software that scans incoming messages for viruses: the open source ClamAV.

The next two sections describe how you configure filtering settings in the Server app, the Configuration Assistant, and in Server Admin. Keep in mind that all three are front ends to the same filtering software. I also describe in more detail the meanings of these settings and how you might use them effectively.

Setting spam and virus blocking with the Server app

To access the filtering settings from the Server app, click Mail in the sidebar and then click the Edit Filtering Settings button. There are three settings, shown in Figure 14-13:

• Enable Virus Filtering: This option is either on or off.
• Enable Blacklist Server Filtering: This check box specifies a blacklist server to prevent spam from known spam servers from reaching you.

  If you select this option, the default is zen.spamhaus.org. You can change this setting, if you like. ...