SPF, which means Sender Policy Framework, is an e-mail safety system, which is used to verify whether an e-mail message is sent by an official server. Employing SPF protection for a domain will stop the forging of emails generated with the domain. In layman's terms: activating this function for a domain creates a specific record in the Domain Name System (DNS) that contains the IP addresses of the servers that are permitted to send emails from mail boxes using the domain. The moment this record propagates worldwide, it will exist on all of the DNS servers that direct the Internet traffic. Any time an email message is sent, the first DNS server it goes through tests whether it originates from an authorized server. When it does, it's forwarded to the destination address, yet when it doesn't originate from a server indexed in the SPF record for the domain, it's discarded. In this way nobody will be able to mask an email address and make it appear as if you are distributing spam. This approach is also known as email spoofing.