SPF, which is an acronym for Sender Policy Framework, is an e-mail protection system, which is employed to confirm if an email message was sent by a licensed server. Using SPF protection for a domain name will prevent the counterfeiting of email addresses made with the domain. In layman's terms: activating this feature for a domain makes a specific record in the Domain Name System (DNS) that contains the IP addresses of the servers that are permitted to send e-mail messages from mail boxes using the domain. As soon as this record propagates globally, it exists on all of the DNS servers that direct the Internet traffic. Whenever an e-mail message is sent, the first DNS server it uses tests if it originates from an approved server. When it does, it's sent to the destination address, but when it doesn't originate from a server listed in the SPF record for the domain, it is rejected. Thus nobody will be able to mask an e-mail address then make it appear as if you're e-mailing spam. This technique is also referred to as email spoofing.