Re: Multiple classes of mail

Mark C. Langston wrote:

> On Wed, Apr 07, 2004 at 06:48:29PM -0400, Meng Weng Wong wrote:
>  
>
> > Instead, perhaps we can borrow another concept from the postal service:
> > different classes of mail.  This lets us treat each class differently,
> > with different expectations. 
> >    
>
> RFC2076 defines two headers that provide for this already:  The
> "Priority:" and "Precedence:" headers.  Sendmail 8.12 already does some
> checking on these headers.
>  
From my reading of Meng's note, it would seem that "Priority:" and 
"Precedence:" could potentially be used by trusted MTAs to indicate to 
an MUA (or a later-hop MTA) that mail was classified into one of these 
classes, but that the actual classification process would be based as 
much on a heuristic (i.e., does the incoming message originate from a 
service which can be validated with CID, DK, etc.) as it would be based 
on fields which could be specified by a sender.
I think that the notion that there are different levels of confidence 
for mail is a correct one and one which end-users typically make today.  
But the analogy to "first-class," "second-class," etc. is an imperfect 
one, since in the traditional paper mail system, class is generally 
specified by the sender based on his or her determination of importance, 
cost, etc.  It's not generally made by the recipient (or by the post 
office).  I believe this distinction is a significant one, especially if 
we intend it as a simpifying assumption for end-users.
-Edwin