Re: [Emailcore] MDAs (was: Re: Delivered-To issues)

[Dave Crocker <[e-mail]>]

On 1/7/2021 1:20 PM, John C Klensin wrote:
> --On Thursday, January 7, 2021 10:16 +0100 Alessandro Vesely
> <[e-mail]> wrote:
>> Some points can be made without splitting hairs.  Defining the
>> concept of MDA only serves to clearly state what is part of
>> SMTP and what is beyond.
> 
> But, AFAICT, that brings things full circle to John L's point.
> If there are some flavors of MDA that are really part of the MTA

the expresses a conditional that is a non-sequitor.  MTAs are not MDAs. 
MDAs are not MTAs.  There are no architectural 'flavors' to this 
distinction.


> function and some flavors that are not, then a crisp definition
> of MDA that would fit well into 5321bis may not be possible
> without splitting exactly those hairs.

Why do you want to create redundant -- or, worse, divergent -- text, 
given that the IETF spent 5 years formulating an architecture document 
that already has it:

> 4.3.3.  Mail Delivery Agent (MDA)
> 
>    A transfer of responsibility from the MHS to a Recipient's
>    environment (mailbox) is called "delivery".  In the architecture, as
>    depicted in Figure 5, delivery takes place within a Mail Delivery
>    Agent (MDA) and is shown as the (D) transition from the MHS-oriented
>    MDA component (hMDA) to the Recipient-oriented MDA component (rMDA).
...


If you have specific concerns about the consensus-based text in the 
document, please state them.




d/


-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net