SPF, which is an abbreviation for Sender Policy Framework, is a verification system that is aimed at stopping the so-called e-mail forging. Essentially, this means sending a message from one email and making it appear to be sent from a different one with the objective to scam in some way the individual getting it. In the event that the SPF protection is activated for a domain name, a record which includes all mail servers authorized to email messages with addresses under the domain is made. The record is placed on all DNS servers that direct the web traffic around the world, therefore they all will recognize whether an email message comes from a valid server or not. The check is performed at the very first server where the e-mail goes through and in the first case the message is forwarded, but in the second one it is removed and it never reaches its intended recipient. Applying SPF records for your domain names will prevent all unwanted people from making use of your email addresses for harmful objectives.