SPF, which is an abbreviation for Sender Policy Framework, is a validation system that is aimed at stopping the so-called email forging. In simple terms, it indicates sending some message from one email and making it look like it’s sent from another one with the objective to scam in some manner the person receiving it. In case the SPF protection is active for a domain, a record which has all mail servers authorized to send messages with addresses part of the domain is created. The record is saved on all the DNS servers that direct the web traffic across the globe, thus they all can recognize if an e-mail message originates from a valid server or not. The check is done at the very first server where the email goes through and in the first case the e-mail message is forwarded, while in the second it is removed and it never reaches the supposed recipient. Employing SPF records for your domains will prevent any unwanted people from making use of your email addresses for malicious purposes.