SPF, which stands for Sender Policy Framework, is an e-mail safety system, that is used to verify whether an email message was sent by an official server. Employing SPF protection for a particular domain name will stop the forging of emails made with the domain. In simple words: activating this attribute for a domain name generates a particular record in the Domain Name System (DNS) containing the IP addresses of the servers which are allowed to send e-mail messages from mail boxes under the domain. As soon as this record propagates worldwide, it will exist on all the DNS servers that route the Internet traffic. Any time a new email message is sent, the initial DNS server it goes through verifies if it originates from an accredited server. In the event it does, it is forwarded to the destination address, but when it does not come from a server indexed in the SPF record for the particular domain, it is discarded. In this way nobody will mask an e-mail address then make it appear as if you're sending spam. This technique is also identified as email spoofing.