WASHINGTON • Mr Ray Tomlinson, the American programmer widely credited with inventing e-mail, has died. He was 74.

Mr Tomlinson invented direct electronic messages between users on different machines on a certain network in 1971. Before then, users could only write messages to others using the same computer.

He also selected the ampersat to be included in an e-mail address as an interface between the user and the computer host. Mr Tomlinson's innovation in e-mail protocols allowed users to send messages to others using different computers, and to do so in a standardised messaging format, including fields such as from, subject and date.

"A true technology pioneer, Ray was the man who brought us e-mail in the early days of networked computers," his employer Raytheon said in a statement. "His work changed the way the world communicates."

A company spokesman said Mr Tomlinson died on Saturday last week, and the cause of death was not yet confirmed.

Originally from Amsterdam, New York, Mr Tomlinson went to school at the Rensselaer Polytechnic Institute and obtained his master's degree in electrical engineering at the Massachusetts Institute of Technology (MIT) in the 1960s.

He went on to work at research and development company Bolt Beranek and Newman - now Raytheon BBN Technologies - when he made his e-mail breakthrough.

When Mr Tomlinson invented the user@host standard for e-mail addresses, it was applied at the US Defence Advanced Research Projects Agency's (Darpa) Arpanet, the Internet's precursor, which connected research organisations in the US in a government-funded programme.

The first message was sent between two machines that were literally side by side, connected only through the Advanced Research Projects Agency Network, or Arpanet, he wrote on his blog.

"When I was satisfied that the program seemed to work, I sent a message to the rest of my group explaining how to send messages over the network. The first use of network e-mail announced its own existence," said Mr Tomlinson.

The program changed the way people communicate, revolutionising how "millions of people shop, bank, and keep in touch with friends and family, whether they are across town or across oceans", said the biography on Mr Tomlinson on the Internet Hall of Fame, where he was inducted in 2012.

AGENCE FRANCE-PRESSE, REUTERS