Re: [ietf-smtp] New Version Notification for draft-crocker-email-deliveredto-00.txt

[Pete Resnick <[e-mail]>]

On 11 Feb 2021, at 20:48, Dave Crocker wrote:

> On 2/11/2021 4:35 PM, Pete Resnick wrote:
>> Also, does adding the Return-Path: happen before or after adding the 
>> Delivered-To:? The spec seems to indicate [after], but it doesn't 
>> mention Return-Path: at all.
>
>
> One is specified in 821 & 822, ff.  The other is specified in this new 
> draft.  Neither is jointly specified.
>
> I haven't noticed anything in the new draft that even mentions them 
> jointly.  Indeed, Received: is only cited in the new draft in the 
> Security Considerations section.
>
> If there is anything in it that produced the 'seems to indicate' 
> impression, I'd like to know what it is, so I can fix it.  Even if 
> they are added by the same process, I would not expect there to be any 
> order dependency.

The examples show Delivered-To: next to the last Received: field, which 
implies that Return-Path: is going to get pre-pended after the 
Delivered-To: field. If in practice they can appear in either order 
(which seems perfectly plausible), that seems like a reasonable thing to 
mention. If in practice they always appear in a particular order (which 
also seems plausible) and some entity later reading the message relies 
on that order (which doesn't seem like a great idea, but weirder things 
have happened), that seems like an important thing to say. Either way, 
setting expectations seems good.

pr
-- 
Pete Resnick https://www.episteme.net/
All connections to the world are tenuous at best