SPF, which is short for Sender Policy Framework, is an e-mail safety system, which is designed to verify if an email message is sent by an official server. Using SPF protection for a domain will prevent the forging of emails made with the domain. In layman's terms: enabling this function for a domain generates a specific record in the Domain Name System (DNS) containing the IP of the servers that are allowed to send email messages from mailboxes under the domain. Once this record propagates worldwide, it exists on all DNS servers that direct the Internet traffic. Any time a new e-mail message is sent, the first DNS server it goes through checks whether it originates from an accredited server. When it does, it is forwarded to the destination address, however when it doesn't come from a server listed in the SPF record for the particular domain, it is discarded. Thus nobody can mask an e-mail address and make it look as if you are e-mailing spam. This technique is also known as email spoofing.