Mailman : Web-based tool to manage your mailing lists
Mailman is a web-based mailing list administration program. Mailman allows people to create mailing lists, and it automates the addition and removal of mailing list members, using a web-based interface. Mailman supports built-in archiving, automatic bounce processing, content filtering, digest delivery, spam filters, and more.
New Mailman lists may be requested by sending an e-mail to help@astro.caltech.edu. Once the list is created, you will receive email with instructions on how to administer your list from a web site. Many existing Mailman lists are available from Astronomy Mailman page.
Within Mailman itself, there is extensive documentation for each option that a subscriber (list member) may set, as well as options that the list owner may set.
Additional Mailman documentation is available from a number of sources on the web: