Many list servers are set up so that replys from recipients are rebroadcast to all the participants of the list, often with "moderation" to prevent abuse (such as commercial messages). Others simply post automatically, but have a size limit for the message (oversize messages are referred to the administrator for review).

Subscribing to a list server usually involves sending an email (often to "majordomo@(whatever)") with the word "subscribe" in the subject line. Unsubscribing is done the same way by sending the subject "unsubscribe". This is an automatic procedure and the list server owner is not involved.

List server software can be found free on the Internet. It is cheap and easy to run a list server if you have a high speed connection to the Internet or can host it on someone else's computer that does.