We use a Google Group for a camp mailing list. Anyone who is camping with us for an event must be on the mailing list at least between the point at which they decide to camp with us and the event, but anyone who has ever camped with us is welcome to stay on the mailing list afterwards. The list is low-traffic except for the weeks before an event we attend.
To join the mailing list, you must be invited by one of our list admins. You may do this either by filling out an application form to camp with us at an event, or by contacting us if you have camped with us before, have left the mailing list, and would like to re-join it.
Members can email the list at universe-discuss@googlegroups.com