The term 'Email Predecessor' refers to two communication methods that preceded the use of email. The first is Telex, which was a teleprinter system that allowed for the transmission of text-based messages over telephone lines. It was developed in the 1930s and was widely used until the 1980s. The second is TELEGRAM, which was a message delivery service that allowed for the transmission of written messages over long distances. It was developed in the 1850s and remained popular until the mid-20th century. Both Telex and TELEGRAM were important predecessors to the development of email, which revolutionized communication in the late 20th century.