SPF, which is an abbreviation for Sender Policy Framework, is a certification system that aims at protecting against the so-called email faking. Essentially, it indicates sending a message from one e-mail and making it seem to be sent from a different one with the purpose to scam in some manner the person receiving it. If the SPF protection is active for a domain, a record which includes all mail servers authorized to send messages with addresses in the domain is created. The record is saved on all DNS servers that direct the web traffic internationally, thus they all will identify whether an e-mail message comes from a trustworthy server or not. The check is conducted at the very first server where the e-mail goes through and in the first case the email message is forwarded, while in the second it's discarded and it never gets to its intended recipient. Employing SPF records for your domains will prevent all unauthorized people from making use of your email addresses for malicious objectives.