SPF, which is an acronym for Sender Policy Framework, is an email security system, which is used to validate whether an email message was sent by an authorized server. Employing SPF protection for a particular domain will stop the faking of email addresses created with the domain. In simple words: enabling this attribute for a domain makes a specific record in the Domain Name System (DNS) containing the IP of the servers which are permitted to send e-mails from mail boxes using the domain. Once this record propagates globally, it will exist on all DNS servers that direct the Internet traffic. When an email message is sent, the first DNS server it uses verifies whether it originates from an authorized server. In the event it does, it is sent to the destination address, but when it does not originate from a server listed in the SPF record for the domain, it is rejected. In this way nobody will be able to mask an email address and make it look as if you are e-mailing spam messages. This method is also known as email spoofing.