SPF, which is an acronym for Sender Policy Framework, is an e-mail safety system, which is is intended to verify whether an e-mail message is sent by a certified server. Using SPF protection for a particular domain will prevent the forging of emails made with the domain. In simple words: activating this function for a domain name creates a particular record in the Domain Name System (DNS) which includes the IP addresses of the servers which are permitted to send email messages from mailboxes under the domain. Once this record propagates worldwide, it will exist on all of the DNS servers that direct the Internet traffic. Every time a new email message is sent, the initial DNS server it goes through verifies if it originates from an accredited server. In the event it does, it is sent to the destination address, yet when it does not come from a server indexed in the SPF record for the particular domain, it is rejected. In this way nobody can mask an e-mail address to make it look as if you're e-mailing spam. This approach is also termed email spoofing.