Apache SpamAssassin™ is a mail filter that identifies spam. It is an intelligent email filter that uses a diverse range of tests to identify unsolicited bulk email, more commonly known as spam. These tests examine email headers and content to classify email with advanced statistical methods. More information is available at spamassassin.apache.org
You can also use "Apache SpamAssassin™" instead of custom mail filter rules. Here, you are able to set the score at which the email is set to be marked as spam. All the emails will be Auto-deleted if it's score matches or is higher.
You can opt not to delete those messages by enabling 'Spam Box' which you can do from the same page. You can view all the emails which are classified as spam in this folder and can remove all the email that you don't require. And, can use few emails which are important but for some reason ended up at spam.
You risk losing your important emails if you configure this service and don't enable Spam Box.
