SPF, which is short for Sender Policy Framework, is an email security system, which is designed to verify if an email message was sent by an authorized server. Employing SPF protection for a particular domain will stop the faking of email addresses made with the domain. In layman's terms: enabling this attribute for a domain makes a particular record in the Domain Name System (DNS) that contains the IP addresses of the servers which are allowed to send emails from mail boxes using the domain. As soon as this record propagates globally, it exists on all DNS servers that direct the Internet traffic. Any time an e-mail message is sent, the initial DNS server it goes through verifies if it comes from an authorized server. When it does, it's sent to the destination address, yet when it does not come from a server listed in the SPF record for the domain, it's discarded. In this way nobody will be able to mask an email address and make it look as if you are e-mailing spam. This approach is also identified as email spoofing.