SPF, which stands for Sender Policy Framework, is an e-mail protection system, that is employed to validate whether an e-mail message is sent by a certified server. Using SPF protection for a domain name will stop the counterfeiting of emails generated with the domain. In layman's terms: enabling this attribute for a domain name makes a particular record in the Domain Name System (DNS) that contains the IP of the servers which are permitted to send emails from mailboxes using the domain. As soon as this record propagates worldwide, it exists on all DNS servers that route the Internet traffic. Any time a new email message is sent, the initial DNS server it goes through verifies if it originates from an accredited server. In the event it does, it's forwarded to the destination address, but when it does not come from a server indexed in the SPF record for the particular domain, it is discarded. In this way nobody will be able to mask an email address then make it look as if you're sending spam messages. This method is also known as email spoofing.