SPF, which is short for Sender Policy Framework, is an e-mail protection system, which is is intended to confirm whether an email message is sent by an authorized server. Employing SPF protection for a given domain will stop the counterfeiting of email addresses generated with the domain. In layman's terms: activating this function for a domain name makes a special record in the Domain Name System (DNS) containing the IP addresses of the servers that are permitted to send e-mail messages from mail boxes using the domain. When this record propagates worldwide, it will exist on all the DNS servers that route the Internet traffic. Whenever an e-mail message is sent, the first DNS server it uses tests if it comes from an accredited server. In the event it does, it's forwarded to the destination address, but when it does not come from a server part of the SPF record for the particular domain, it's rejected. In this way nobody will be able to mask an e-mail address and make it appear as if you're e-mailing spam. This method is also called email spoofing.