To switch on spam filtering for a mailbox:
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. These settings are fine if you prefer to filter mail with a filtering program installed on your local computer – once mail has been retrieved from your mailbox.
If you rely entirely on the server's spam filter, you may configure it so as to automatically delete the suspicious messages as they come. To configure the spam filter, follow the instructions below.