MailSpammer is a simple mailing list manager for smaller e-mail lists, using procmail and Perl. MailSpammer does not require administrator access, aside from initial setup (creating e-mail aliases), and features subscription, unsubscription, moderation, and archiving. The goal is not to be a majordomo-alike mailing list manager, but instead to provide a lightweight way to handle basic list management tasks.
The Simple Mail Distributor is an Email::Filter-based Perl script which can be used to implement an administratively-managed mailing list. The service can be restricted to a list of allowed senders. Each message is sent individually with the To header adjusted to match the recipient.