SPF, which abbreviates Sender Policy Framework, is a verification system that is aimed at preventing the so-called e-mail faking. In simple terms, this means sending a message from one email address and making it look like it’s sent from a different one with the objective to scam in some way the person opening it. In case the SPF protection is active for a domain, a record that includes all mail servers authorized to send messages with addresses within the domain is made. The record is saved on all DNS servers that route the web traffic worldwide, therefore they all will recognize whether an email message originates from an authentic server or not. The check is conducted 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 discarded and it never gets to its intended recipient. Using SPF records for your domains will stop all unauthorized people from making use of your emails for harmful purposes.