everyone knows what email is, and most people, are also members of email lists too. Unfortunately, everyone also knows about SPAM, but not everyone knows how to defend the email inbox In an effort to curtail SPAM, the CAN-SPAM act 2003, enacted by Congress, was passed to defend your email inbox. That’s over 19 years ago, and no revisions. It was and is an effective method to limit unwanted messages: but as a law, it did not address the technical obstacles and fundamental problems that remain; therefore, SPAM continues to be delivered to inboxes. SPAM, being annoying, misleading, and costly was the catalyst that spurred email authentication. Email authentication is the process by which an ISP can verify the identity of the email sender. Email authentication started around 2004 with SPF. This was developed in response to SPAMMERS using forged emai l addresses (also known as spoofing) to get their messages delivered. Today, SPF continues to be one way to defend the email inb