SPF, which is an abbreviation for Sender Policy Framework, is an authentication system that aims at blocking the so-called email counterfeiting. Essentially, this indicates sending some message from one e-mail address and making it look like it’s sent from a different one with the purpose to scam in some manner the person opening it. If the SPF protection is running for a domain name, a record that includes all mail servers authorized to send messages with addresses part of the domain is generated. The record is kept on all DNS servers that route the web traffic all over the world, so they all can identify whether an email 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 message is forwarded, while in the second one it is removed and it never gets to its intended recipient. Employing SPF records for your domain names will prevent any unwanted people from making use of your email addresses for harmful purposes.