SPF, which is an acronym for Sender Policy Framework, is an email protection system, that is is intended to confirm whether an e-mail message is sent by a licensed server. Using SPF protection for a domain name will stop the counterfeiting of emails made with the domain. In simple words: enabling this attribute for a domain generates a particular record in the Domain Name System (DNS) which contains the IP of the servers which are permitted to send email messages from mail boxes under the domain. As soon as this record propagates globally, it exists on all of the DNS servers that route the Internet traffic. When a new email message is sent, the initial DNS server it uses tests whether it comes from an official server. If it does, it is sent to the destination address, however when it doesn't originate from a server indexed in the SPF record for the particular domain, it's rejected. In this way nobody can mask an email address then make it appear as if you are distributing spam messages. This method is also called email spoofing.