A term that refers to standards, such as Sender ID, SPF and DomainKeys/DKIM, that serve to identify that an email is really sent from the domain name and individual listed as the sender. Authentication standards are used to fight spam and spoofing.

Building a Highly-targeted Opt in List: When Money Lies Beneath the Lists
Are you successful with your Internet business? Better yet, do you think you are successful with your online business? When most online entrepreneurs are asked with these questions, they often brush it off.