SPF, which stands for Sender Policy Framework, is an email safety system, which is employed to confirm whether an email message was sent by an official server. Employing SPF protection for a particular domain will stop the faking of email addresses created with the domain. In layman's terms: enabling this feature for a domain makes a specific record in the Domain Name System (DNS) containing the IP addresses of the servers that are allowed to send email messages from mailboxes under the domain. Once this record propagates worldwide, it will exist on all of the DNS servers that direct the Internet traffic. Any time an e-mail message is sent, the initial DNS server it uses verifies whether 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 listed in the SPF record for the particular domain, it's discarded. In this way nobody can mask an e-mail address to make it look as if you are distributing spam. This method is also called email spoofing.