0: http://oss-security.openwall.org/wiki/mailing-lists/distros
On the other hand schleuder exists today and can be used by normal people (for example without having a custom private key per list, as you need afaik for [SELS]).
The other often overlooked fact about schleuder is that it's also a re-mailer. You can use it in a one-to-many setting, where the external party does only know the cryptographic key and email address of the list and a group of people can communicate with this person using schleuder as the proxy. This is a great alternative to shared mailboxes and a feature that is probably impossible with proxy encryption.
[SELS] https://slagell.info/Adam_J._Slagell/Past_Projects_files/khu...
This doesn't present a problem, because you can construct anonymous group signature schemes.
Heh. In practice this is true, but only for sufficiently advanced values of "you". I certainly wouldn't feel comfortable attempting such a thing without consulting a real cryptographer.
The other benefit is that membership management is a lot easier. Usually the first time you tell members to add or remove a key, things start falling apart quickly. Schleuder makes that easy.
I suppose if you know about that then it is ok.
The benefit of this approach over the alternative (making people encrypt and sign with a lot of keys) is that once received, the content does not give away the key names of the other mailing list members.