SPF, which is short for Sender Policy Framework, is an e-mail protection system, that is used to confirm whether an email message is sent by an authorized server. Using SPF protection for a given domain name will stop the counterfeiting of emails generated with the domain. In layman's terms: activating this attribute for a domain name creates a special record in the Domain Name System (DNS) containing the IP of the servers that are permitted to send email messages from mailboxes using the domain. As soon as this record propagates globally, it exists on all DNS servers that route the Internet traffic. Every time some email message is sent, the first DNS server it goes through tests whether it originates from an authorized server. If it does, it is forwarded to the destination address, yet if it does not originate from a server part of the SPF record for the particular domain, it is rejected. In this way nobody will mask an e-mail address to make it appear as if you are e-mailing spam. This technique is also called email spoofing.