SPF, which stands for Sender Policy Framework, is an e-mail safety system, which is employed to validate if an e-mail message was sent by an authorized server. Using SPF protection for a particular domain name will stop the counterfeiting of email addresses created with the domain. In simple words: activating this feature for a domain name makes a particular record in the Domain Name System (DNS) that contains the IP of the servers that are permitted to send emails from mail boxes using the domain. When this record propagates globally, it exists on all DNS servers that route the Internet traffic. Every time some email message is sent, the initial DNS server it uses tests whether it comes from an authorized server. When it does, it's forwarded to the destination address, yet if it does not originate from a server indexed in the SPF record for the domain, it's rejected. Thus nobody will mask an e-mail address to make it appear as if you are distributing spam messages. This approach is also identified as email spoofing.