Most mailing lists are intended for discussion of a specific topic. List members post questions and comments to the list, and other people respond.
Some members read their e-mail regularly, post messages often, and respond quickly to questions.
Others read their e-mail infrequently, and respond when they get around to it. To join a mailing list, send the subscribe command to the appropriate list server. To remove yourself from a list, send the unsubscribe or signoff command to the same list server. Note that command formats may vary, depending on the list serving software used by the list. A mailing list is controlled by software called a list server.