SPF, which is an abbreviation for Sender Policy Framework, is an authentication system that is aimed at stopping the so-called e-mail counterfeiting. Essentially, this means sending a message from one email address and making it look like it’s sent from another with the objective to scam in some way the person receiving it. In the event that the SPF protection is active for a domain, a record that includes all the mail servers authorized to email messages with addresses within the domain is generated. The record is kept on all DNS servers that direct the web traffic internationally, so that they all can recognize whether an e-mail message originates from a valid server or not. The verification is done at the first server where the email goes through and in the first case the message is forwarded, and in the second it is discarded and it never gets to its intended recipient. Applying SPF records for your domains will stop any unauthorized people from using your emails for harmful objectives.