Listserv, Mailbase, Llstproc And Other Mailing List Servers.
A Listserv is a type of Mailing List program (though it is also sometimes used generically as another word for all mailing list programs). Other programs used to fulfil this function are mailbase, listproc, majordomo. All have similar functions and similar (but sadly not identical) commands. These programs function as servers: sent something by you they will respond, even if only to tell you that they did not understand what they were sent.