Postorius

Postorius is a Django‑based web interface that lets users interact with GNU Mailman 3 mailing‑list software through a browser. It provides the typical list‑management pages—subscription handling, archive browsing, and configuration of list settings—without requiring command‑line access. The application runs on Python 3.9+ and requires Django 4.2 or newer, while depending on a running Mailman 3.3.10 instance.

The tool is aimed at administrators and members of mailing‑list communities who prefer a graphical UI for managing subscriptions, moderating messages, and adjusting list preferences. Because it is self‑hostable and open‑source under GPL‑3.0, it can be deployed on private servers or integrated into existing infrastructure without subscription fees.

Postorius originates from contributions made during Google Summer of Code and is maintained by the Free Software Foundation. It is considered stable and is distributed without warranty, offering a free‑tier solution for organizations that need a web front‑end to GNU Mailman.