SPF, which is an abbreviation for Sender Policy Framework, is a verification system that is aimed at blocking the so-called e-mail counterfeiting. Essentially, this means sending some message from one email and making it look like it’s sent from another one with the objective to scam in some manner the individual getting it. If the SPF protection is active for a domain name, a record that contains all of the mail servers authorized to send messages with addresses in the domain is created. The record is stored on all the DNS servers that route the Internet traffic globally, so that they all will identify if an email message originates from a valid server or not. The check is performed at the first server where the e-mail goes through and in the first case the message is forwarded, while in the second it's discarded and it never gets to the supposed recipient. Employing SPF records for your domain names will prevent any unwanted people from using your email addresses for harmful objectives.