Re: [ietf-smtp] Fwd: I-D Action: draft-melnikov-smtp-metadata-00.txt

["Rolf E. Sonneveld" <[e-mail]>]

On 03/22/2015 10:52 PM, Alexey Melnikov wrote:
> On 22/03/2015 21:13, John R Levine wrote:
>>>> So I think it would work fine if people implemented it, but unless
>>>> there's a very concrete use case and people ready write and deploy
>>>> those implementations, I wouldn't bother.
>>> Fair comment, see use case examples in the document.
>>
>> I don't understand the benefit of putting the headers in a separate 
>> chunk.
> See my reply to Stephan. I admit, I haven't decided myself how useful 
> this might be.
>> Setting suggested IMAP flags seems easy to do in a header if someone 
>> wants to do that.
> It bothers me that we keep minting new SMTP extensions. There was an 
> SMTP/LMTP extension proposal for passing IMAP flags.
> Stuff like DSN parameters could have been done as transaction state 
> block 0. I know it is too late to change DSN, but I am wondering if 
> doing something more generic would be useful.
>
> The third use case is key material exchange a la DarkMail, but I will 
> see if there is any interest in that idea.

a fourth use case might be, for MLM's to make a diff between:

a) original message and
b) the message the MLM will distribute

and to send this diff along with the original DKIM-Signature in a 
'container'. The receiver MTA could reconstruct the original message and 
verify the original DKIM-Signature (and e.g. apply DMARC).

/rolf