SPF, which means Sender Policy Framework, is an email protection system, that is used to verify if an e-mail message is sent by a licensed server. Employing SPF protection for a given domain will stop the faking of emails made with the domain. In simple words: activating this function for a domain makes a particular record in the Domain Name System (DNS) which includes the IP of the servers that are allowed to send e-mail messages from mail boxes under the domain. When this record propagates globally, it will exist on all DNS servers that route the Internet traffic. Any time an e-mail message is sent, the first DNS server it goes through checks whether it originates from an authorized server. In the event it does, it is sent to the destination address, yet if it does not originate from a server listed in the SPF record for the particular domain, it is rejected. In this way nobody will be able to mask an email address then make it appear as if you're sending spam. This approach is also identified as email spoofing.