Re: UUCP, etc., and SMTP/822/MIME mail (was: Re: I-D ACTION:draft-hoffman-utf8headers-00.txt)

Martin Duerst wrote:


>This is a valid point, and it seems to lead to an interesting question
>that I haven't seen discussed yet: For the SMPT extension proposed in
>Paul's draft, and for Charles' header, what's the policy with respect
>to stuff encoded with RFC 2047? In detail:
>
>- Is a message tagged with Charles' header allowed to contain RFC 2047 stuff?
>   (I would propose we say: MAY contain RFC 2047-encoded stuff)

I prefer not to have a header, only negotiation before transfer of data.
If a header is used (there is a problem with a header due to it have to
be before all other headers to simplify message handling), the rules should
be the same as fpr SMTP negotiated UTF-8.

>- Is a message passed over SMTP with UTF-8-HEADERS allowed to contain
>   RFC 2047 stuff? The way I understand SMTP extensions (experts on this
>   list, please correct me if I'm wrong), this is a somewhat moot question,
>   because it's the server that says what extensions it supports; the client
>   doesn't say which extensions it uses (unless through the use of
>   parameters in commands, but there are none for UTF-8-HEADERS).
>   So my understanding is that RFC 2047-encoded headers are not disallowed.

When MTAs have negotiated for UTF-8, only UTF-8 should be used - not RFC 2047.
(the only exception to that rule could be to send characters not in UCS).
The reason for this is to simplify handling of headers (parsing, decoding etc).
When UTF-8 is negotiated no RFC2047 handling should be needed.

>- Does 'upgrade' include conversion from RFC 2047-encoded headers to
>   raw UTF-8 (even if the RFC 2047 encoding doesn't use UTF-8)?
>   I didn't find this in Paul's current draft; there is at the moment
>   not yet much about upgrading overall. I would propose we say
>   "upgrading MUST convert RFC 2047-encoded text to UTF-8 if the charset
>   used in the RFC 2047-encoding is UTF-8, and SHOULD (or MAY?) convert
>   RFC 2047-encoded text to UTF-8 if the charset used in the
>   RFC 2047-encoding is not UTF-8.

As I said above for negotiate, when you go UTF-8, only UTF-8 shall be
used otherwise much of the good with UTF-8 goes away (and some will
implement UTF-8 as RFC2047 encoded text to avoid going UTF-8).
So when a gateway goes from lagacy to UTF-8 is must decode all
RFC2047 (and other into ASCI encodings) into UTF-8.

   Dan