SPF, which is short for Sender Policy Framework, is an e-mail safety system, that is employed to confirm whether an e-mail message is sent by a certified server. Using SPF protection for a given domain name will prevent the counterfeiting of emails created with the domain. In simple words: enabling this feature for a domain name generates a special record in the Domain Name System (DNS) which contains the IP addresses of the servers which are allowed to send e-mails from mailboxes using the domain. When this record propagates worldwide, it exists on all the DNS servers that route the Internet traffic. Whenever some email message is sent, the first DNS server it uses checks whether it comes from an official server. In the event it does, it is forwarded to the destination address, however when it does not come from a server indexed in the SPF record for the domain, it is discarded. In this way nobody can mask an e-mail address then make it appear as if you are distributing spam messages. This method is also called email spoofing.