Bijan Parsia writes:
> Sure. Let's say I make a category, 'foo'. Into it, I put a number of
> messages, sorted by hand.
>
> Now, I want to share that category with you. Since, a category is a just a
> list of msgIDs, themselves bearing no inherent relation, If I just give
> you the category...no dice. My msgID won't match up *in any way* with
> yours.
>
> Perhaps I'm being presumptuous. Normally, if you share a mail folder, I
> imagine you send the actual messages within. Bummer.
>
> Email sucks! :)
>
> But the total break between msgID and content, the arbitrariness of the
> association, *does* imho make categories a bit less useful. But maybe I'm
> hallucinating :)

No, it only means that message IDs must be computable from the content only,
and that independent computations on the same content yield the same result.
Some sort of message digest like MD5 is the answer, but only if you can
guarantee the content is identical.  If it isn't, I'm not sure I see the
point of the exercise, since you would be sharing something other than what
you think you're sharing.

-- Duane