SPF, which is an abbreviation for Sender Policy Framework, is a certification system that aims at stopping the so-called e-mail counterfeiting. In simple terms, this means sending a message from one email and making it seem to be sent from another with the objective to scam in some way the person receiving it. When the SPF protection is activated for a domain name, a record that contains all the mail servers authorized to email messages with addresses part of the domain is created. The record is kept on all the DNS servers that route the web traffic around the world, so that they all can recognize if an email message comes from an authentic server or not. The verification is done at the first server where the e-mail goes through and in the first case the message is forwarded, and in the second it is removed and it never reaches the supposed recipient. Employing SPF records for your domains will prevent any unauthorized people from making use of your email addresses for malicious objectives.