SPF, which stands for Sender Policy Framework, is an email protection system, that is designed to confirm if an email message was sent by a licensed server. Employing SPF protection for a given domain name will stop the forging of emails generated with the domain. In layman's terms: enabling this feature for a domain name makes a particular record in the Domain Name System (DNS) that contains the IP addresses of the servers which are allowed to send e-mail messages from mail boxes using the domain. When this record propagates globally, it will exist on all the DNS servers that route the Internet traffic. Every time a new email message is sent, the first DNS server it uses tests if it originates from an official server. If it does, it's sent to the destination address, but when it does not come from a server part of the SPF record for the particular domain, it is discarded. Thus nobody can mask an e-mail address then make it look as if you are e-mailing spam messages. This method is also referred to as email spoofing.