> The view I have been trying to put across is that the point where
> normalization occurs is the weakest link in the system, and that
> therefore such points should be concentrated so that they are few
> in number and easily fixed. From that POV, User Agents fail on both counts.
The view is over-simplistic for at least two reasons. First is that
you're comparing systems of very different total complexity -
you will not rid UAs of the burden of supporting unicode (including
normalization) but you are adding complexity to parts of the system
that don't need to support unicode, thus adding more opportunities
for failure. In other words, your proposal is adding more weak links
without strengthening the weak links that you're worried about.
Second, you're failing to consider that there's essentially no incentive
for a significant percentage of the world's mail users or MTA operators
to upgrade. An approach that relies on MUA upgrades to provide the new
functionality lets those who benefit from the new functionality - those
who have an incentive - do the upgrade and get immediate benefit. This
gets it deployed more quickly for those users who need it.
I think this is the key issue.
People in the UK, USA (and a large percentage of Europe) won't want to
fiddle with things that ain't broke just so that some people can send them
emails that they can't understand... This means that the majority of
Internet users will be running mail systems which people using IDN
wouldn't be able to contact in the near/mid future.
IMHO, some people seem to be missing a key problem. If people start having
(for instance) email addresses which can ONLY be shown using Chinese
characters, how on earth is the average westerner supposed to send them an
email message (ie they won't be able to type in the email address)? All
non-latin email addresses/domains would either have to have a latin
equivalent, or would just have a scope of the country of origin. If all
addresses have to have a latin equivalent, then, simply, why not use that
for all the 'important' stuff, and just use the local script for display
purposes. If you want Chinese (for instance) emails just to have a scope of
China, then why not have a new set of protocols ('UDNS', 'USMTP' etc) which
handle Unicode addressing, with gateways run by ISPs in those countries to
convert 'USMTP' to SMTP to go to the rest of the world.
(Just to throw another daft idea into the ring :-) )
Paul VPOP3 - Internet Email Server/Gateway
paul(_at_)pscs(_dot_)co(_dot_)uk http://www.pscs.co.uk/