SPF, which is an acronym for Sender Policy Framework, is an email protection system, which is is intended to confirm if an e-mail message is sent by a licensed 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 function for a domain generates a particular record in the Domain Name System (DNS) containing the IP of the servers which are permitted to send e-mails from mailboxes under the domain. When this record propagates globally, it will exist on all DNS servers that route the Internet traffic. Every time some e-mail message is sent, the first DNS server it uses verifies whether it comes from an accredited server. When it does, it is forwarded to the destination address, yet when it does not originate from a server indexed in the SPF record for the particular domain, it is rejected. In this way nobody will mask an email address and make it look as if you're e-mailing spam. This technique is also known as email spoofing.