FAQ? how to set up a cross-platform encrypted mailing list/forum

[Joseph Ashwood]

Well it's not an easy way, but it's a functional way. Take the code for GPG
and the code for your favorite open-source list server, integrate them so
that each mailing list has it's own GPG key, decrypts, reencrypts to the
targets (individually so as to avoid having insane sizes for each message)
sends, repeat. If you need higher speeds you can compromise of the encrypt
to targets by choosing a key periodically, encrypting it to all the targets
and holding it to be combined with the header.

I would recommend against an S/MIME solution. S/MIME has a great many weak
solutions, and take a lot of work before it's really ready for secure
purposes.
                            Joe