His death was confirmed by another internet pioneer, Vinton Cerf.
Tomlinson joined Bolt Beranek and Newman (now known as Raytheon BBN Technologies) in 1967 and while there he came up with the idea of using the @ symbol to separate usernames from their host computers.
Until then, messages could be sent only between users of the same computer. Tomlinson combined the SNDMSG and CPYNET programs to come up with ARPAnet's first program for network email.
Tomlinson helped develop the TENEX operating system. He is also known for being involved in creating standards for the from, subject, and date fields which are part of every email message.
The first email, sent between two computers sitting besides each other, used the ARPANET connection between them.
"I have seen a number of articles both on the internet and in print stating that the first email message was 'QWERTYUIOP'. 'Taint so," he wrote.
"My original statement was that the first email message was something like 'QWERTYUIOP'. It is equally likely to have been 'TESTING 1 2 3 4' or any other equally insignificant message.
"Apparently I didn't hedge the statement enough because this got turned into bald statements that 'QWERTYUIOP' was the first email message. Probably the only true statements about that first email are that it was all upper case (shouted) and the content was insignificant and forgettable (hence the amnesia)."
Tomlinson was born in New York and attended the Broadalbin Central School. He attended the Rensselaer Polytechnic where he obtained a bachelor's degree in electrical engineering in 1963. He obtained a master's degree in the same field from the Massachusetts Institute of Technology in 1965. He is ranked at four on the MIT list of top 150 innovators and ideas from MIT.