Schleuder

Schleuder operates as an email gateway for groups, allowing members to exchange OpenPGP‑encrypted messages directly through the list while also handling mail from and to non‑subscribers. It receives encrypted messages from subscribers, decrypts and re‑encrypts them as needed, and forwards them to the appropriate recipients, providing a seamless remailing capability that bridges private and public communication channels.

The system is intended for users who need a self‑hostable, free‑tier solution for secure mailing list management without subscription fees. It is open‑source under GPL‑3.0, making it suitable for individuals, organizations, or communities that prioritize privacy, personal emancipation, and social or political freedom in their communications.

Documentation is organized for three roles—subscribers, list administrators, and server administrators—guiding each through configuration, usage, and maintenance. Development contributions are welcomed via the issue tracker, and participants are asked to follow the project's code of conduct.