In order to prevent having to read through a lot of unwanted commercial e-mails, you can enable Spam Assassin. Spam Assassin uses a point system to decide whether e-mails should get through to your inbox or be blocked.Blocked e-mails will either be sent to your spam folder or automatically deleted.
Under the filters setting you can change the score which will trigger blocking. If you have not used Spam Assassin before, you should start out with the default setting of 5.0 , turn off auto-delete and enable the spam folder. If too much spam is getting through then lower the value slowly until you are happy with the results. If too many items are being blocked then you can raise the value to 8.1 and adjust it from there to suit your needs.
Under configuration you will see spaces labeled whitelist from: You can manually add full email addresses: firstname.lastname@example.org, or whole domains *@somedomain.com. You may also use a ‘?’ single wild card characters.
Above this is an area with 4 spaces labeled score. Here you can add your own rules using this format:“score” “TEST_NAME” “1 to 4 positive or negative numbers”
Be sure to omit the quote marks.
e.g. score INVALID_DATE 2
Do not add your own rules on an important email account before practicing on an unimportant one.