SPF, which is short for Sender Policy Framework, is an e-mail protection system, that is is intended to verify if an email message is sent by a certified server. Employing SPF protection for a domain will stop the faking of emails created with the domain. In simple words: activating this feature for a domain makes a specific record in the Domain Name System (DNS) which includes the IP of the servers that are permitted to send email messages from mail boxes under the domain. The moment this record propagates worldwide, it exists on all DNS servers that route the Internet traffic. When an e-mail message is sent, the initial DNS server it goes through tests if it originates from an approved server. In the event it does, it is forwarded to the destination address, yet when it doesn't come from a server listed in the SPF record for the particular domain, it is discarded. Thus nobody will be able to mask an email address then make it appear as if you are e-mailing spam messages. This method is also known as email spoofing.