SPF, which abbreviates Sender Policy Framework, is a validation system that is aimed at preventing the so-called email forging. In simple terms, it indicates 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 person receiving it. In case the SPF protection is running for a domain name, a record which includes all mail servers authorized to send messages with addresses part of the domain is made. The record is kept on all DNS servers that route the Internet traffic across the globe, so they all will identify if an email message originates from a trustworthy server or not. The check is performed at the first server where the email goes through and in the first case the email message is forwarded, but in the second one it is removed and it never reaches the supposed recipient. Applying SPF records for your domain names will stop any unauthorized people from making use of your emails for harmful objectives.