SPF, which stands for Sender Policy Framework, is an e-mail security system, which is employed to validate if an email message is sent by a licensed server. Employing SPF protection for a domain will stop the counterfeiting of emails made with the domain. In simple words: enabling this attribute for a domain creates a specific record in the Domain Name System (DNS) containing the IP addresses of the servers which are allowed to send email messages from mail boxes using the domain. As soon as this record propagates worldwide, it exists on all the DNS servers that direct the Internet traffic. Every time an e-mail message is sent, the first DNS server it goes through verifies if it comes from an official server. When it does, it is forwarded to the destination address, but when it doesn't come from a server part of the SPF record for the particular domain, it is discarded. In this way nobody can mask an email address and make it appear as if you're sending spam messages. This approach is also identified as email spoofing.