Re: [idn] internationalized email addresses

[Keith Moore <moore@cs.utk.edu>]

> > There is little point in considering local parts now unless they
> > additionally constrain the problem. (AFAIK they do not.)
> 
> Actually, they do.

agreed.  I'm not sure that IDN is the place to discuss it, but
there are several potentially hairy issues associated with using
ACE for local-parts.  including: 

- dots in local-parts (are they ACE encoded or do we just encode 
the atoms and leave the dots alone?) 
- quoted-strings, and the potential for multiple representations
- specials (other than ".") within a local-part which is ACE-encoded
- similarly for other Unicode characters that resemble specials

now it's quite possibly the case that all of these can be worked out
satisfactorily, and it Sure Would Be Nice if the same encoding
routine that is used for IDNs could also be used for local-parts
of an email address.  but it's a bit of a leap to say that whatever
ACE is chosen for IDNs will Just Work for local-parts.

Keith