SPF, which is an abbreviation for Sender Policy Framework, is a validation system that is aimed at preventing the so-called e-mail counterfeiting. Essentially, this means sending some message from one email address and making it seem to be sent from another with the objective to scam in some way the person getting it. In case the SPF protection is active for a domain name, a record that includes all of the mail servers authorized to send messages with addresses part of the domain is made. The record is saved on all of the DNS servers that direct the Internet traffic all over the world, so they all will recognize whether an e-mail message originates from an authentic server or not. The verification is done at the first server where the email goes through and in the first case the e-mail message is forwarded, whereas in the second one it is removed and it never reaches the intended recipient. Employing SPF records for your domains will stop any unauthorized people from making use of your emails for harmful objectives.