Plesk allows for setting up and using black lists and white lists for filtering mail at the server level as well as at the user level.
The user level spam filter functionality is available for each specific mail name configured as a mailbox. That means that the Mailbox functionality should be activated for the selected mail name.
If the spam filtering functionality is enabled for users by the Administrator, it should first be activated. To do that:
You will see the Spam Filter icon become active (displayed in colour), meaning that the spam filtering functionality is now available for this mail name. If the spam filtering functionality was not enabled for the users by the Administrator, the Enable spam filtering checkbox at the Mailbox management page will be inactive and the Spam Filter icon will also be inactive (displayed in grey).
Click on the Spam Filter icon to access the Spam filter configuration page, where you can set the filtering rules for the selected mail name.
If the Administrator has set up and activated mail filter at the server level, all the incoming mail will be processed with it before it reaches the users’ mailboxes. You can choose to use or, on the contrary, not use the server wide settings for your mail. If you decide not to use the server wide settings, those will be disregarded and your mail will be processed only according to the configuration you set at the user level.
In order to recognize a mail message as spam it needs to score a certain amount of hits. The hits are scored according to the internal SpamAssassin settings and based on the contents of the mail messages and its subject. You can change the sensitivity of the spam filter by varying the amount of hits required for marking a message as spam. The more hits are required the less sensitive the filter is, and vice versa – the less hits are required the more sensitive the filter is.
You can choose what to do with the mail recognized as spam: you can choose to either delete it, or to mark it as spam and leave it in the mailbox.
If you decide to leave the mail recognized as spam in your mailbox such messages will be marked correspondingly so that they can be easily visually identified. In particular, a special string is added to the subject of the message (e.g., by default the string *****SPAM***** will be added to the spam messages subjects). You can change this string (or tag) to whatever you like, or even to disable this option.
Black list is a list of E-mail addresses, which are automatically considered as sending unsolicited mail – spam. Therefore, all messages coming from the E-mail addresses that match those specified in the black list will automatically be marked as spam.
You can add to the black list either exact E-mail addresses or patters, using wildcards (‘*’, e.g.: entry ‘*@spammers.online.com will cause all messages coming from the domain spammers.online.com be marked as spam, regardless of what the exact mail name is).
The Administrator’s black list section contains the server wide black list entries that were added by the Administrator. If you chose to use the server wide filtering settings (the Use server wide settings checkbox checked) you may wish to edit this section by removing unnecessary entries. To do that, just select the Administrator’s black list entry and click Remove.
White list contains E-mail addresses, which are automatically considered as trustworthy. Therefore, all messages coming from the E-mail addresses that match those specified in the white list will never be marked as spam.
You can add to the white list either exact E-mail addresses or patters, using wildcards (‘*’, e.g.: entry ‘*@your-company.com will cause all messages coming from the domain your-company.com not be marked as spam, regardless of the content of a message).
The Administrator’s white list section contains the server wide white list entries that were added by the Administrator. If you chose to use the server wide filtering settings (the Use server wide settings checkbox checked) you may wish to edit this section by removing unnecessary entries. To do that, just select the Administrator’s white list entry and click Remove.