posterity is a work in progress, aimed at providing another messaging-forum mechanism, as an alternative to traditional mailing lists and newsgroups. Mailing lists suffer from a range of problems including bounce handling, autoresponders, privacy of the membership list, and malicious subscription or unsubscription of third parties. Newsgroups are better in these areas, but introduce their own limitations, including the difficulty of creating a new group, no immediate notification of new messages, and failing to present a synchronized, consistent set of messages to all readers. New alternatives such as Web-based discussion boards have some advantages, but email and news are far more mature in having well-developed clients. Taking the position that email's problems are the easiest to solve, I will discuss how public, read-only IMAP gives us the best of all worlds.