Setting Up SpamAssassin Spam Filter

To switch on SpamAssassin spam filter:

  1. Click Server shortcut in the navigation pane.
  2. Click Mail in the Services group.
  3. Select Spam Filtering tab.
  4. To allow server wide filtering based on the settings you define, select the Use server-wide settings check box.
  5. To let your users set their own spam filtering preferences on a per-mailbox basis, select the Allow personal settings check box.

    Now all the incoming mail will be filtered on the server side. By default, spam filter does not delete spam mail, it only adds the "X-Spam-Flag: YES" and "X-Spam-Status: Yes" headers to the message, and "*****SPAM*****" text string to the beginning of Subject line of each message recognized as spam.

    If you have enabled the Allow personal settings option, then your users will be able to set their spam filters so as to automatically delete junk mail. They will also be able to set up their personal black and white lists of correspondents that will override the server settings, and teach the spam filter on a per-mailbox basis.

  6. Adjust the spam filter sensitivity by specifying the desired value in the Hits required for spam box.

    SpamAssassin performs a number of different tests on contents and subject line of each message. As a result, each message scores a number of points. The higher the number, the more likely a message is spam. For example, a message containing the text string "BUY VIAGRA AT LOW PRICE!!!" in Subject line and message body scores 8.3 points. By default, the filter sensitivity is set so that all messages that score 7 or more points are classified as spam.

  7. Specify how to mark messages recognized as spam.

    At the server level, you cannot set the server-wide spam filter to automatically delete spam: you can do it only on a per-mailbox basis. So, for the server-wide policy, you can choose only marking messages as spam: "X-Spam-Flag: YES" and "X-Spam-Status: Yes" headers are added to the message source by default, and if you want, the spam filter will additionally include a specific text string to the beginning of Subject line. To include a desired combination of symbols to the message subject, type it into the by tag box. If you do not want the spam filter to modify message subject, clear the Modify spam mail subject check box. If required, specify the spam detection alert text in the appropriate field.

  8. Define the language characteristics of mail that should always pass the filter by specifying trusted languages and locales.
  9. Once finished with setting up SpamAssassin spam filter, click Up Level to return to the previous screen.

If you wish to adjust spam filtering settings for a specific mailbox, proceed to the Protecting Mailboxes from Spam section.