Complete manual/402/en

Encrypted lists: If you want a high level of security, there is also the possibility of having mailing lists that provide end-to-end encryption, which—if used correctly on uncompromised devices—means that only the senders and recipients will be able to read the content of messages. However, it is important to understand that this requires all list participants to be experienced in using Pretty Good Privacy (PGP) or Gnu Privacy Guard (GPG). This type of list is called a Schleuder list (http://schleuder2.nadir.org/ , developed by https://www.nadir.org/), and is designed to serve as a tool for group communications with a strong emphasis on security beyond just having encrypted connections using SSL/TLS. Be aware, however, that setting up a Schleuder list can require command line skills, and that the project hasn’t been kept fully up to date and documented as of writing.