Raymond Tomlinson, the inventor of modern email and a technological leader, has died, his employer said Sunday.

Tomlinson died Saturday, the Raytheon Co. said; the details were not immediately available.

Email existed in a limited capacity before Tomlinson in that electronic messages could be shared amid multiple people within a limited framework. But until his invention in 1971 of the first network person-to-person email, there was no way to send something to a specific person at a specific address.

Tomlinson wrote and sent the first email on the ARPANET system, a computer network that was created for the U.S. government that is considered a precursor to the Internet. Tomlinson also contributed to the network’s development, among numerous other pioneering technologies in the programming world.