It provides a central email address that everybody can send their messages to, and then resends those messages to everybody on the list.
Some lists are primarily for announcements only while others maintain regulars discussions.
In general, lists are under some form of control, either moderated or requiring administrator approval to subscribe. This list is a once every week or so update on what is new at Cybernude and other sites as well as nudism in general. It is administered by Rick Jaggers. Most of the participants of the list are either students, faculty, or recent graduates. The list is maintained by Rick Jaggers.