There are hundreds of legal discussion groups on the Internet. Two of the most popular mailing list software programs are Listserv and Majordomo. Listserv disputes that it has become a generic name just as Kleenex disputes is has become the generic name for any soft tissue. Listserv and similar software provide the capability to mass-distribute messages that form conferences and allow the archiving of files and messages that can be searched and retrieved. Learn about the group before attempting to join.
Many lists have a strong sense of community and appropriate behavior.
Even when a group is public, it is wise to spend a week or two listening to the group before speaking up. Most lists receive email at a central server and then forward that message to any mailbox that has subscribed to the mailing list. To subscribe to a list, all you need is email software. When you have subscribed to a list, messages are automatically forwarded to your email inbox. A newsgroup message is not automatically forwarded to your email but instead is posted where it can be read by anyone.