SPF, which means Sender Policy Framework, is an email protection system, which is used to confirm if an email message is sent by a licensed server. Using SPF protection for a given domain name will stop the faking of emails made with the domain. In layman's terms: enabling this attribute for a domain name generates a specific record in the Domain Name System (DNS) containing the IP addresses of the servers which 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 direct the Internet traffic. When an e-mail message is sent, the initial DNS server it uses tests if it originates from an accredited server. When it does, it's forwarded to the destination address, yet when it doesn't come from a server part of the SPF record for the particular domain, it's discarded. In this way nobody can mask an email address then make it appear as if you're e-mailing spam. This technique is also termed email spoofing.