Securing Email of your own Domain - SPF, DKIM and DMARC

The Simple Mail Transfer Protocol (SMTP) does not have any intrinsic methods of proving the authenticity, integrity, and confidentiality of individual messages. Over the decades, multiple additional protocols have been developed in order to address these three basic weaknesses of email. Some serve to prove the identities of users of the email protocol (PGP/GPG or other public key cryptography based on individuals), while others are more focused on proving the authenticity and integrity of any email from a particular domain. In this article, we will explore three protocols of the latter category.