SPF, which is an acronym for Sender Policy Framework, is an email protection system, that is is intended to confirm if an email message is sent by an authorized server. Employing SPF protection for a particular domain name will stop the counterfeiting of emails made with the domain. In simple words: enabling this attribute for a domain name generates a particular record in the Domain Name System (DNS) which includes the IP of the servers which are permitted to send e-mails from mailboxes under the domain. Once this record propagates globally, it exists on all of the DNS servers that route the Internet traffic. When an email message is sent, the first DNS server it uses verifies if it comes from an approved server. If it does, it is sent to the destination address, however if it doesn't originate from a server part of the SPF record for the domain, it is discarded. In this way nobody will mask an email address to make it appear as if you're e-mailing spam. This method is also termed email spoofing.