SPF, which stands for Sender Policy Framework, is an e-mail protection system, that is used to verify if an e-mail message was sent by a certified server. Using SPF protection for a domain name will prevent the faking of email addresses created with the domain. In layman's terms: enabling this attribute for a domain name generates a particular record in the Domain Name System (DNS) containing the IP of the servers that are allowed to send emails from mailboxes using the domain. When this record propagates worldwide, it exists on all the DNS servers that direct the Internet traffic. Every time an email message is sent, the first DNS server it goes through tests if it originates from an approved server. If it does, it is forwarded to the destination address, yet when it does not originate from a server part of the SPF record for the domain, it's discarded. Thus nobody can mask an e-mail address and make it appear as if you are distributing spam messages. This technique is also identified as email spoofing.