Raymond Samuel Tomlinson (April 23, 1941 – March 5, 2016) was an American computer programmer who implemented the first email program on the ARPANET system, the precursor to the Internet, in 1971; It was the first system able to send mail between users on different hosts connected to ARPANET.
In 1967, he joined the technology company of Bolt, Beranek and Newman (now BBN Technologies), where he helped develop the TENEX operating system including the ARPANET Network Control Program, implementations of Telnet, and implementations on the self-replicating programs Creeper and Reaper. He wrote a file transfer program called CPYNET to transfer files through the ARPANET.