SPF, which is short for Sender Policy Framework, is an e-mail safety system, that is used to confirm whether an email message is sent by an official server. Employing SPF protection for a domain will stop the counterfeiting of emails created with the domain. In layman's terms: activating this feature for a domain name makes a particular record in the Domain Name System (DNS) which includes the IP addresses of the servers that are permitted to send emails from mail boxes using the domain. The moment this record propagates globally, it will exist on all DNS servers that direct the Internet traffic. Any time some email message is sent, the initial DNS server it uses tests if it comes from an official server. When it does, it's forwarded to the destination address, but if it does not originate from a server listed in the SPF record for the domain, it is discarded. Thus nobody can mask an e-mail address to make it appear as if you're sending spam messages. This technique is also termed email spoofing.