On Sun, Jun 06, 2021 at 02:56:55PM -0400, John Levine wrote:
I still don't think it's worth opening up RFC 6531 unless we have a
lot more to change.
I can continue to ignore the suggested use of U-labels in trace headers
without a document revision, and without any consequente
interoperability downsides. So there's not much impetus for change
If we're really looking for surgery patient, that'd be RFC6532, in which
message/global is a major design blunder. It blatantly breaks a key
feature of the design of MIME, in which for good reason composite parts
did not get non-identity transfer encodings.
It is perhaps still not too late (given low adoption) to fix the
blunder, by deprecating message/global. Bounces of EAI messages can
either optimistically include UTF-8 characters in the headers of nested
messages, or conservatively bounce just a "text/rfc822-headers" portion,
which being non-composite can be transfer-encoded:
bouncing just the headers is a good idea anyway, since it reduces
the odds of the bounces getting lost in transit for being overly
large, or triggering false positives in filters, ...
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