SPF, which abbreviates Sender Policy Framework, is an authentication system that aims at protecting against the so-called e-mail forging. Essentially, this indicates sending some message from one email address and making it seem to be sent from a different one with the objective to scam in some manner the individual opening it. In the event that the SPF protection is active for a domain name, a record that contains all the mail servers authorized to send messages with addresses within the domain is generated. The record is stored on all DNS servers that direct the Internet traffic worldwide, therefore they all will identify whether an e-mail message originates from an authentic server or not. The check is conducted at the very first server where the email goes through and in the first case the e-mail message is forwarded, while in the second it is removed and it never reaches the supposed recipient. Applying SPF records for your domains will prevent any unwanted people from using your emails for harmful objectives.