SPF, which is an acronym for Sender Policy Framework, is an email safety system, which is is intended to verify if an email message is sent by a certified server. Employing SPF protection for a particular domain name will prevent the faking of emails generated with the domain. In simple words: activating this feature for a domain name makes a special record in the Domain Name System (DNS) which includes the IP addresses of the servers that are allowed to send e-mails from mailboxes using the domain. As soon as this record propagates globally, it will exist on all the DNS servers that direct the Internet traffic. Any time some email message is sent, the first DNS server it uses tests if it originates from an authorized server. When it does, it is forwarded to the destination address, however if it does not originate from a server part of the SPF record for the particular domain, it is rejected. Thus nobody will mask an e-mail address and make it appear as if you are sending spam. This technique is also termed email spoofing.