Just to name names: I know that Cyberdog on the Macintosh and Microsoft's
new mail and news offering (the latter for which I don't know the release
status) both produce multipart/alternative by default (without "by-hand"
user manipulation) for certain types of messages.
Sheesh, now that you mention it, there's another MUA that does this too --
Ishmail. I completely forgot about it.
So that's three MUAs producing multipart/alternative.
Well, that is considerable progress, although it would be nice
to know
-- what types of messages
and
-- what really acts on these on receipt, other than treating
them as "mixed".
Ishmail also handles this on receipt. That makes three MUAs I know of,
Pine, Ishmail, and Metamail, that handle multipart/alternative.
Ned