SPF, which means Sender Policy Framework, is an e-mail safety system, that is is intended to confirm whether an email message was sent by an authorized server. Employing SPF protection for a particular domain name will prevent the counterfeiting of emails created with the domain. In layman's terms: activating this feature for a domain name creates a specific record in the Domain Name System (DNS) which includes the IP of the servers that are allowed to send e-mails from mailboxes under the domain. When this record propagates worldwide, it exists on all the DNS servers that route the Internet traffic. Any time an e-mail message is sent, the first DNS server it uses tests if it originates from an official server. In the event 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 domain, it is discarded. In this way nobody can mask an e-mail address and make it appear as if you're sending spam messages. This technique is also termed email spoofing.