BTW, do any of the current proposals deal with 822-compliant messages
which are not MIME compliant?
Security multiparts deal with this case as well. MIME can be used to carry RFC
822 messages that aren't themselves MIME-compliant, which means that security
multiparts can be used on non-MIME messages as well. This facility just falls
out of existing MIME facilities in a very clean and natural fashion.
Is 822 dead?
Of course it isn't dead. Every MIME message is also an RFC 822 message, so RFC
822 lives on as part of MIME in any case. I also doubt that we'll ever see a
day where every message sent is in MIME format. Every MIME agent also has
to be prepared to deal with non-MIME material as well.
Are there plans to strip
out the non-MIME-compliant parts?
There are no such parts to strip. Arbitrary RFC 822 messages can be carried by
MIME.
If someone could point me to an
existing document that addresses this issue, I would appreciate it.
There is no such document because there is no issue that needs to be addressed.
There are lots and lots of real issues along these lines, but they have nothing
to do with RFC 822 per se. There are many types of messages floating around
that comply with neither MIME nor with RFC 822. (Actually, the encapsulation
rules in MIME allow for considerably greater flexibility than RFC 822 does, so
MIME effectively extends RFC 822 so that it can carry messages that could not
otherwise be transported legally.)
I know of no documents that address this sort of thing, however. Since by
definition such messages are nonstandard you really cannot have a
standards-track document that talks about them, and nobody has bothered with
any informational specifications along these lines to the best of my knowledge.
Ned