Re: I-D ACTION:draft-hoffman-utf8headers-00.txt

>> the possibility exists that the gateway isn't aware of the utf-8
>> extension, so it injects messages with utf-8 headers and addresses
>> into the legacy mail system without doing a conversion.
>
> Yes, that's a good argument that UTF-8 header fields are likely to
> fall unexpectedly into the hands of software that doesn't know how
> to handle them.  If UTF-8 header fields use the same field names as
> the corresponding ASCII header fields, there's no telling what will
> happen.  By using new never-before-used field names for the UTF-8 
> header
> fields (or even an entirely different header format) we could avoid 
> that
> pitfall.

but using new field names for utf-8 versions of existing fields has 
other pitfalls - e.g. that the utf-8 and ascii versions can get out of 
sync, that the utf-8 fields will get converted to 2047 or bit-stripped, 
etc.