SPF, which is short for Sender Policy Framework, is an email safety system, that is designed to confirm if an email message was sent by an authorized server. Employing SPF protection for a domain name will prevent the counterfeiting of emails made with the domain. In layman's terms: enabling this attribute for a domain generates a particular record in the Domain Name System (DNS) which includes the IP addresses of the servers which are permitted to send email messages from mailboxes using the domain. When this record propagates worldwide, it will exist on all of the DNS servers that route the Internet traffic. Any time a new e-mail message is sent, the initial DNS server it goes through tests if it comes from an official server. In the event it does, it's sent to the destination address, yet when it doesn't come from a server indexed in the SPF record for the particular domain, it is rejected. In this way nobody will be able to mask an e-mail address to make it appear as if you are sending spam. This technique is also termed email spoofing.