Alfie John wrote:

On Tue, Feb 7, 2012, at 11:34 AM, Charles T. Brooks wrote:

...

Non-english character sets are going to become part of hostnames and DNS. That's inevitable.

Mail addresses are based on DNS hostnames.

Ergo, mail attributes will one day need to support all possible characters.

Thanks for that. It makes sense and it was enough to convince me to submit a bug.

None of this has any significance until someone writes a new spec and submits it to the IETF for approval.