A discussion list can provide a discussion forum without geographic constraints, allow for sharing of expertise and resources, provide quick responses to queries, and can provide current information about a topic of discussion. Many discussion groups are archived and topics of past discussion can be searched. If you find that a list isn't for you, you can unsubscribe from it.
Some lists are very active and can generate many messages per day.
For more active lists, there is often a digest version where all the messages are compiled for a day or several days and sent in one message. Many lists utilize software such as listserv, listproc, mailbase, mailserv, or majordomo to handle routine administrative functions, such as subscribing, temporarily suspending receipt of messages, receiving the digest version, or retrieving an archived file. Internet Directory . Fawcett Columbine, 1994. 1994 Directory of Electronic Journals, Newsletters and Academic Discussion Lists .