American Online (AOL) is one of the main managers of mail in the Internet industry. AOL like other mail management provides good services in terms of methods of mailing lists and profiles. The optimization of email and spam filtering is also part of the AOL service. Indeed AOL makes clear the runway for their email users.
Sender Policy Framework (SPF) has been adopted by AOL to fight spam. SPF does not literally block spam unlike spam filters and spam busters. What SPF does is it keeps the real addresses from being forged, and thus prevent misdirected email (bounce emails) on legitimate sources – protected again soon. Spammers forge addresses to hide the true identity, and to prevent bounced emails from their inboxes. With SPF user know if the email sender is genuine or fake.
Furthermore SPF let users specify send their policy. Whenever a policy is taken by the user, the domain owner publishes this policy. And when mail cut someone receives a message indicating came from that domain, a recipient of cut can check if indeed the message is legitimate by checking out published policy. With this, proper evaluation of the email can be done. When messages are proven false, then it can be marked as unwanted or unsolicited.