SPF, which abbreviates Sender Policy Framework, is a verification system that aims at stopping the so-called email counterfeiting. Essentially, this indicates sending a message from one e-mail and making it look like it’s sent from a different one with the purpose to scam in some way the person receiving it. If the SPF protection is active for a domain, a record that contains all the mail servers authorized to send messages with addresses in the domain is generated. The record is kept on all of the DNS servers that route the web traffic around the world, so that they all will identify if an email message originates from a trustworthy server or not. The check is done at the very first server where the e-mail goes through and in the first case the e-mail message is forwarded, but in the second it is removed and it never reaches its intended recipient. Applying SPF records for your domain names will stop all unwanted people from using your email addresses for harmful purposes.