Re: DISCUSS and COMMENT: draft-ietf-sieve-refuse-reject

Aaron Stone wrote:

> Less verbose, previous paragraph for context:
>
> """
> Introduction
> ...
>   This document also describes how to use reject/ereject at varying
>   points in the email stack: Mail Transfer Agent (MTA), Mail Delivery
>   Agent (MDA), and Mail User Agent (MUA). See [EMAIL-ARCH] for a
>   comprehensive discussion of these environments.
>
>   This document also specifies the use of a Delivery Status
>   Notification [DSN] instead of an MDN when appropriate. In general,
>   an MDN is a human-oriented status, generated by an MUA, while a
>   DSN is a machine-oriented status, generated by an MTA.
> """"
>
> On Mon, 2008-11-17 at 08:06 -0800, Aaron Stone wrote:
>  
>
> > On Fri, 2008-11-14 at 13:54 +0000, Alexey Melnikov wrote:
> >    
> >
> > > Hi Pasi,
> > > My apologies for the delayed response:
> > >
> > > Pasi Eronen wrote:
> > >      
> > >
> > > > Discuss:
> > > >        
> > [snip]
> >    
> >
> > > > The document says the main difference between 'reject' and 'ereject'
> > > > is that the latter allows SMTP/LMTP level rejection (and there are
> > > > some details about non-ASCII strings).  I think I understand this
> > > > part, but it seems there's another difference: the former talks about
> > > > sending an MDN, while the latter sends a DSN.
> > > >        
> > > Correct. I would consider MDN versa DSN to be a minor difference.
> > >      
> > >
> > > > I'm not that familiar with the distinction between MDNs and DSNs (and
> > > > on first reading, thought they meant the same thing),
> > > >        
> > > They are very similar syntactically. Semantically, DSN is for reporting 
> > > delivery status (don't involve a human), while MDN is for reporting user 
> > > processing status, such as message read, deleted without reading, etc.
> > >      
> > >
> > > > and I think the
> > > > document would benefit from short description here, reminding readers 
> > > > that they're not the same thing, and explaining why 'reject' and 
> > > > 'ereject' do things differently.
> > > >        
> > > The reason why MDNs were chosen in the first place, because reject 
> > > action could be implemented in a Mail User Agent. The MUA is not allowed 
> > > to generate DSNs, because the message was already delivered to user's 
> > > mailbox. At this point only MDNs can be generated.
> > > What happened after RFC 3028 came out was that many more Sieve engines 
> > > running inside MTAs or MDAs were developed. For them, generating MDN 
> > > might be a bit awkward.
> > > So I am not entirely convinced that stating this difference is going to 
> > > be very useful. Please let me know if you still think otherwise.
> > >      
> > I accidentally left an editor's mark in the -08 draft I just posted, and
> > mis-attributed the sentence above as [[[arnt's text]]]. I wanted to
> > possibly put this into the document to describe the difference of MDN
> > vs. DSN.
> >
> > Proposed text:
> > """
> >   This document also specifies the use of a Delivery Status
> >   Notification [DSN] instead of an MDN when appropriate. In general,
> >   an MDN is generated by an MUA or MDA, and can be used to indicate
> >    
I can see MDA generating a DSN, so I would remove MDA from the above line.

> >   the status of a message with respect to its recipient, while a DSN
> >   is generated by an MTA, and can be used to indicate whether or not
> >   a message was received and delivered by the mail system. In other
> >   words, an MDN is a human-oriented status while a DSN is a
> >   machine-oriented status.
> > """
> >
> > I'll flip the location of this paragraph in the introduction wrt the paragraph 
> > that introduces the reference to EMAIL-ARCH so that MTA, MDA and MUA are 
> > already defined at this point.
> >
> > Like it? Dislike it? Don't care?
> >    
This looks fine to me otherwise.

But, I think we still need to discuss in the WG whether this text should 
be added. A topic for today's Sieve WG meeting.