SPF, which abbreviates Sender Policy Framework, is a certification system that aims at protecting against the so-called e-mail forging. In simple terms, this indicates sending some message from one e-mail address and making it seem to be sent from another with the purpose to scam in some manner the individual getting it. When the SPF protection is running for a domain name, a record that contains all of the mail servers authorized to email messages with addresses in the domain is created. The record is stored on all DNS servers that route the web traffic around the world, so that they all will identify if an email message comes from a valid server or not. The check is performed at the very first server where the email goes through and in the first case the message is forwarded, and in the second it is removed and it never reaches its intended recipient. Employing SPF records for your domains will prevent any unwanted people from making use of your emails for malicious purposes.