This seems like a quite elegant solution. I'm very surprised by the second
sentence - are these clients that have difficulty with many Content-Types
or is it a specific issue for message/rfc822?
Only message/rfc822. E.g. it took iOS a couple of years to start supporting it
properly. And it is one of the better mobile email clients.
Brian sent me a message/rfc822 wrapped version of his message, so I
stuffed it into my Gmail, Yahoo, and Hotmail mailboxs after looking at
it in Apple mail and Thuderbird and of course Alpine. Gmail flattens
it to look like a text forward, Yahoo loses the headers on the
wrappped message, Hotmail and Apple mail show it as an attachment you
can download, Thunderbird and Alpine show all the relevant bits, but
not in a particularly attractive way.
In practice it's worse than rewriting the From: line to the mailing
list's address, which is already far from good.
R's,
John