>> Hmm. In emacs, if I try to reply to the message from notmuch-search, I
>> get
>> no error but there is no quoted text from the original message in the
>> reply body and all I see is the 'on <date>, <person> wrote:' citation.
>> Replying from notmuch-show gives me the error I mentioned previously.
>
> I suppose the main difference is the setting of
> notmuch-multipart/alternative-discouraged. If I copy your setting I also
> get an error replying in notmuch-show mode.
>
I know this was mentioned earlier but just to avoid any doubt, my
discourage setting is currently:
(setq notmuch-multipart/alternative-discouraged '("text/plain"))
I removed the "multipart/related". (I agree it's probably not wise to
discourage it).