Providing Certified Mail Services on the Internet

Even though email is an increasingly important application, the Internet doesn´t yet provide a reliable messaging infrastructure. Thus, an email message´s sender can never be certain - and doesn´t receive any evidence -that his or her message was actually delivered to and received by its intended recipients. Furthermore, a recipient can always deny having received a particular message, and the sender can´t do much to prove the opposite. This lack of evidence for message delivery and reception is actually a missing piece in the infrastructure required for the more widespread and professional use of email. Against this background, several value-added services come to mind such as non-repudiation services and the digital analog of certified mail. In this article, the author addresses the problem of how to provide certified mail services on the Internet, focusing on the two-party scenario