SPF, which abbreviates Sender Policy Framework, is a verification system that is aimed at preventing the so-called e-mail forging. In simple terms, this indicates sending some message from one e-mail and making it seem to be sent from another one with the objective to scam in some way the individual opening it. When the SPF protection is activated for a domain, a record that contains all mail servers authorized to send messages with addresses part of the domain is generated. The record is saved on all DNS servers that route the web traffic all over the world, so that they all can identify if an email message originates 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, whereas in the second one it is removed and it never reaches the supposed recipient. Using SPF records for your domain names will stop all unauthorized people from making use of your email addresses for harmful objectives.