Definition - What does READMAIL mean?
READMAIL is is the retrieval and reading portion of an early messaging program pair known as SNDMSG and READMAIL written by Ray Tomlinson of Bolt, Beranek and Newman (now BBN Technologies) in 1971. The program was designed to be used on the PDP-10 computer using the BBN-designed TENEX OS. TENEX was one of the more popular OS being used on the PDP-10 at that time.
Techopedia explains READMAIL
At the time of Tomlinson's invention, most email programs were designed to be used in time-sharing systems, which was the usual case for PDP-10 computers. Tomlinson wanted to send messages outside of systems that used the time-sharing scheme. Tomlinson has just finished with his CPYNET file transfer protocol earlier and then experimented with attaching SNDMSG and READMAIL to the protocol. The protocol was able to take the messages from one computer and then drop them into another, which made it possible to send messages outside time-sharing systems. These experiments made by Tomlinson on SNDMSG and READMAIL led to the sending of emails over the ARPANET, the early version of the Internet.