Amongst the casualties of the electronic age has been a number of institutions and the values and services associated with them. One example of such is the postal service and the concept of sealed, private correspondence. The universal postal service was one of the great social developments of the 19th century. Today, while such services continue to exist in almost every country in the world, much of the traffic that they formerly managed has been displaced by various forms of electronic communication. While this has brought benefits, it has also involved some losses. One loss has been the privacy of the sealed letter. This paper describes a project to develop a system to reinstate the concept of private correspondence in an electronic age.