SPF, which means Sender Policy Framework, is an email safety system, which is employed to validate whether an e-mail message was sent by an authorized server. Employing SPF protection for a given domain will prevent the counterfeiting of email addresses made with the domain. In simple words: activating this function for a domain creates a particular record in the Domain Name System (DNS) which includes the IP of the servers that are allowed to send emails from mail boxes under the domain. When this record propagates globally, it will exist on all the DNS servers that direct the Internet traffic. When a new email message is sent, the first DNS server it goes through checks if it comes from an authorized server. In the event it does, it is forwarded to the destination address, however if it does not come from a server part of the SPF record for the domain, it is discarded. In this way nobody will mask an e-mail address to make it look as if you're e-mailing spam messages. This method is also termed email spoofing.