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#### Setting Up SpamAssassin Spam Filter

To switch on SpamAssassin spam filter:

1. On your Home page, open the Server group title menu, and select Spam Filter Settings.
2. To allow server wide filtering based on the settings you define, select the Switch on server-wide SpamAssassin spam filtering check box.
3. To let your users set their own spam filtering preferences on a per-mailbox basis, select the Apply individual settings to spam filtering check box.
4. If you wish to adjust the amount of system resources the spam filter should use (available only for Linux hosting), type the desired value from 1 to 5 into the Maximum number of worker spamd processes to run (1-5) box (1 is the lowest load, and 5 is the highest). We recommend that you use the default value.
5. If you wish to adjust the spam filter's sensitivity, type the desired value in the The number of points a message must score to be considered 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.

   - When your users receive lots of spam messages with the current setting, to make filter more sensitive, try setting a lesser value in the The score that a message must receive to qualify as spam box; for example, 6.
   - When your users are missing e-mails because your spam filter thinks they are junk, try reducing filter sensitivity by setting a higher value in the The score that a message must receive to qualify as spam box.
6. To reduce the load on your Windows server, you can select the Do not filter if mail size exceeds specified size check box and specify the maximum size of the message that the spam filter will test. Recommended mail size limit is 150 - 250 Kbytes, which is usual for mail messages in HTML format with images. The size of the mail is considered critical for filter and server overload when it exceeds 500 Kbytes, which is usual for mail messages containing attachments.
7. To make sure that the spam filter on your Windows server is not leaving some e-mail messages unchecked (this can happen if the amount of incoming mail is very large), limit the number of e-mail messages that can be checked simultaneously in the Number of threads that spam filter can create field.
8. 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 or words to the message subject, type it into the Add the following text to the beginning of subject of each message recognized as spam box. If you do not want the spam filter to modify message subject, leave this box blank. If you want to include into the subject line the number of points that messages score, type _SCORE_ in this box.

9. If you use Parallels Plesk Panel for Windows, define the language characteristics of mail that should always pass the filter by specifying trusted languages and locales.
   - Select the required items from the boxes under Trusted languages and Trusted locales and click Add >>.
   - Letters written in the specified languages and with the defined character sets will not be marked as spam.
10. If you do not want your users to receive e-mail from specific domains or individual senders, click the Black List tab, and then add the respective entries to the spam filter's black list:
    - To add entries to the black list, click Add Addresses. If you have a list of entries stored in a file, click Browse to specify it, and then click OK. Otherwise, select the From List option, and type the e-mail addresses into the E-mail addresses box. Place each address in one row, or separate addresses with a coma, a colon, or a white space. You can use an asterisk (*) as a substitute for a number of letters, and question mark (?) as a substitute for a single letter. For example: address@spammers.net, user?@spammers.net, *@spammers.net. Specifying *@spammers.net will block the entire mail domain spammers.net. To save the entries you added, click OK, then confirm adding, and click OK again.
    - To remove entries from the black list, under the Black List tab, select the entries and click Remove. Confirm removal and click OK.
11. If you want to be sure that you and your users will not miss e-mail from specific senders, click the White List tab, and then add e-mail addresses or entire domains to the spam filter's white list:
    - To add entries to the white list, click Add Addresses. If you have a list of entries stored in a file, click Browse to specify it, and then click OK. Otherwise, select the From List option, and type the e-mail addresses into the E-mail addresses box. Place each address in one row, or separate addresses with a coma, a colon, or a white space. You can use an asterisk (*) as a substitute for a number of letters, and question mark (?) as a substitute for a single letter. For example: address@mycompany.com, user?@mycompany.com, *@mycompany.com. Specifying *@mycompany.com will add to the white list all e-mail addresses that are under the mycompany.com mail domain. To save the entries you added, click OK, then confirm adding, and click OK again.
    - To remove entries from the white list, under the White List tab, select the entries and click Remove. Confirm removal and click OK.
12. Once finished with setting up the spam filter, click OK.

    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 Apply individual settings to spam filtering 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.

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