Fortune (March 7) -- Dr. Shiva Ayyadurai has once again rebuffed claims that Ray Tomlinson was the father of traditional email, claiming instead that he invented it. In the 1960s, however, a number of multi-user computer systems had message-delivery systems with “inboxes” to allow users to communicate with one another. The most famous was the Compatible Time-Sharing System at MIT. But there also was messaging software on the PLATO computer system at Illinois.