SPF, which means Sender Policy Framework, is an e-mail safety system, that is used to verify if an email message is sent by a certified server. Employing SPF protection for a particular domain will prevent the faking of emails made with the domain. In simple words: enabling this feature for a domain name generates a specific record in the Domain Name System (DNS) which includes the IP of the servers which are allowed to send e-mails from mail boxes using the domain. When this record propagates globally, it exists on all DNS servers that route the Internet traffic. When some email message is sent, the first DNS server it goes through verifies whether it originates from an official server. If it does, it's forwarded to the destination address, however if it does not originate from a server indexed in the SPF record for the particular domain, it is discarded. Thus nobody can mask an e-mail address then make it look as if you are distributing spam. This approach is also termed email spoofing.