Re: First strawman for UTF-8 headers proposal

At 10:33 AM +0100 11/28/03, Thomas Roessler wrote:
>On 2003-11-26 10:57:57 -0800, Paul Hoffman / IMC wrote:
>
>>  - If a receiving SMTP server does not support UTF-8-HEADERS, the
>>  sending SMTP client downgrades all headers and continues to send
>>  the message.
>
>...
>
>>  - If the initiator knows the mapping for any recipient (through caching
>>  or an address book), they SHOULD put it in the map header. If they
>>  don't include a mapping and the message hits a non-UTF-8-HEADERS
>>  SMTP server, the message will bounce.
>
>What happens to the envelope?  I'm reading the current proposal to
>mean that mail transfer agents would have to rewrite the envelope
>based on parsing the address-map header in the message, and bounce
>if no address-map is present.

That was my intention, yes.

>What to do about BCCs, then?  Adapted mapping headers for each
>instance, in order to avoid information leakage?

The originating client would just do their own local fallback. If 
none is available, the message doesn't get sent.

Yes, we would need to deal with Bcc handling carefully.

>I'm also having some doubts about what will happen when messages are
>sent to mixed universe (utf8/non-utf8) recipient set (or are
>automatically bounced to systems outside utf8 universe; think
>webmail systems).  I'll try to elaborate on this later today.

Please do. I didn't see a problem with this in my first guesses, but 
I easily could have missed something.

--Paul Hoffman, Director
--Internet Mail Consortium