Re: what is the real problem?

>> I suspect it makes more sense to have senders' MUAs include 1 or more 
>> addresses for each sender or recipient (including a required "worst 
>> case" one in ASCII),
>
> And force the sending user to type in multiple addresses per recipient?

no, of course that would never fly.  I'm working on a proposal, but I'd 
like to get the pieces put together before presenting it to the group, 
lest the individual pieces get shot down for lack of a complete picture.

Keith