Re: [exim] IDN, UTF-8 and Punycode curiosity

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Autor: Phil Pennock
Dla: exim-users
Temat: Re: [exim] IDN, UTF-8 and Punycode curiosity
On 2012-01-03 at 12:49 +0200, Warren Baker wrote:
> On Tue, Jan 3, 2012 at 11:40 AM, Cyborg <cyborg2@???> wrote:
> > Am 03.01.2012 10:11, schrieb Mark Elkins:
> >
> > You have to use in your backend .. nothing else will
> > work.
> I have never used it, but doesn't setting allow_utf8_domains and
> adjusting dns_check_names_pattern do the job?

It depends upon the client software; the official IETF approach is to
use Punycode, but another approach is to just put UTF-8 straight into
DNS -- the argument (which I agree with) is that those who want to work
with that part of the world which needs this will upgrade DNS and those
who don't won't, and it's a lot less work to support UTF-8 than to
support Punycode translations everywhere. Mind, normalisation is still

I personally run with those two settings, but to my knowledge I've never
sent or received mail which depended upon them. One of the TODO items
on my plate is Punycode support in Exim, to better play with the IETF
vision of how complex the world should be.

I haven't yet had time to do so.

In practice, for reasons of "that's what my employer cares about", any
work I put into internationalised domains in Exim will focus first on
whatever consensus has formed amongst real-world operators in Japan.
For me, everything else is a nice extra. Other Exim developers may have
other priorities.