SPF, which is short for Sender Policy Framework, is an e-mail security system, which is is intended to confirm if an e-mail message is sent by an official server. Employing SPF protection for a particular domain name will stop the counterfeiting of emails generated with the domain. In simple words: enabling this attribute for a domain name generates a particular record in the Domain Name System (DNS) that contains the IP of the servers that are allowed to send e-mails from mailboxes using the domain. Once this record propagates worldwide, it exists on all DNS servers that route the Internet traffic. Every time some email message is sent, the first DNS server it goes through tests whether it comes from an official server. In the event it does, it is sent to the destination address, yet if it does not originate from a server indexed in the SPF record for the domain, it's rejected. In this way nobody will mask an email address and make it appear as if you are distributing spam messages. This technique is also identified as email spoofing.