Digest subscriptions Some lists, generally those with a high volume of messages transmitted daily, offer you a choice as to how you receive them. Regular subscribers receive messages individually throughout the day. Digest subscribers periodically receive long e-mail messages composed of all the individual messages that were sent to the list since the last digest was sent. You may receive one or more digests a day, depending on the list traffic. Some mailing lists are unmoderated, meaning that every message posted is automatically sent to members of the list.
Moderated lists are usually private lists as well.
Not all lists are open to the public. For example, some lists maintained on Duke's Majordomo server are used by private groups.