SPF, which is an acronym for Sender Policy Framework, is an e-mail protection system, which is is intended to validate if an email message was sent by a licensed server. Using SPF protection for a domain name will prevent the forging of email addresses created with the domain. In layman's terms: activating this attribute for a domain name makes a special record in the Domain Name System (DNS) which contains the IP of the servers that are permitted to send emails from mail boxes under the domain. When this record propagates globally, it will exist on all the DNS servers that route the Internet traffic. Any time a new email message is sent, the first DNS server it goes through verifies if it comes from an official server. In the event it does, it is sent to the destination address, however when it doesn't come from a server listed in the SPF record for the domain, it's discarded. Thus nobody can mask an e-mail address then make it appear as if you're e-mailing spam. This approach is also known as email spoofing.