Re: Can we back up a bit and ask some basic questions?An alternate model

Paul Hoffman / IMC <[email protected]> writes:

> At 2:05 AM -0500 2/24/03, Edmon Chung wrote:
>>http://www.ietf.org/internet-drafts/draft-chung-imax-00.txt
>
> This doesn't address any of the issues that I raised with John's
> proposal of IMAA-UTF8, and in fact brings in many more horrible
> problems like bad charset mappings and forcing a client fallback.

That is a problem?  Not supporting anything else than UTF-8 is a
problem with IDNA and IMAA in the real world.  The bad charset
mappings exist with IDNA/IMAA too, only that they are disguised by an
assumption in the specifications.  As long as not every machine on the
Internet uses UTF-8 you must handle conversion and fallback at some
point.  I'd advocate solutions that tries to face and solve that
problem, instead of hiding the problem by assuming the real world only
uses Unicode.

(I'm not saying the proposed fallback mechanism is the perfect one
though, I'm sure it can be improved.)

> What is the actual deployment advantage of a ESMTP extension over just
> plain IMAA-ACE?

It makes SMTP support non-ASCII for email addresses.  Compared to
using IMAA-ACE, the advantage is that an ESMTP extension doesn't
require the use of a punycode encoder/decoder.  What would the actual
deployment advantage of using IMAA-ACE over an ESMTP extension with an
ACE fallback be?

> If the MUA or the MTA that is about to write to the message store
> needs to be able to act differently based on different input, which
> is true in all the proposals so far, wouldn't a solution that has
> zero effect on SMTP be better than one that requires a complete
> infrastructure upgrade (IMAA-UTF8) or one that has an optional
> infrastructure upgrade and requires an IMAA-ACE "fallback"?

If you want to deploy as fast as possible and only require changes in
transport end points, yes.  If you want to upgrade to a clean and
easily maintined design in the long-term, no.

An optional infrastructure upgrade and ACE fallback sounds good to me.
Then in 20 years time where all machines to use Unicode, we can relax
the ACE fallback into a MAY and eventually get rid of it.