Russ Allbery <rra(_at_)stanford(_dot_)edu>
Requiring that an autoresponder handle RFC 2047 decoding and MIME
disassembly and reassembly of the original message is a pretty hefty
requirement for a poor little autoresponder.
An e-mail responder which sees a 2047-encoded header field has three
possibilities:
1. Don't include that header field in the reply's body.
2. Include it properly decoded.
3. Include it in raw form.
IMO it's reasonable for forbid option 3. That mandates detection of
2047/mime, but it makes decoding and encoding optional.
And it really isn't the end of the world if a Subject line shows up in the
body of the text RFC 2047 encoded.
It also isn't the end of the world to leave the subject line out if it
can't be shown in a human-readable format. IMO it's better to say nothing
than to say =?big5?b?637826478367487647682132637836363?=.
--Arnt