There are two types of LISTSERVs:

• Open Lists - Allow anyone to subscribe to and sometimes reply to emails that are sent. Anyone can join an open list.
• Closed Lists - Only the list owner can add people to the list. Users require permission to subscribe to a closed list. Generally, the owner of the list will add you to a list of subscribers, and allow you to reply to the list if necessary.

Owners have more administrative work to do on closed lists than open lists.

Every LIST needs an owner to take care of administrative issues.

Once you have been added to a list, you are considered to be a subscriber to that list.