SPF, which is an abbreviation for Sender Policy Framework, is an authentication system that is aimed at blocking the so-called email forging. In simple terms, it indicates sending some message from one e-mail address and making it look like it’s sent from another with the objective to scam in some manner the individual receiving it. In case the SPF protection is running for a domain, a record that contains all of the mail servers authorized to send messages with addresses under the domain is created. The record is stored on all DNS servers that direct the Internet traffic all over the world, therefore they all will recognize if an email message comes from an authentic server or not. The verification is performed at the very 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 intended recipient. Using SPF records for your domain names will prevent any unauthorized people from making use of your emails for malicious objectives.