Re: Working Group Last Call for draft-ietf-sieve-refuse-reject-00.txt

On 8/19/05 11:13 AM, Mark E. Mallett sent forth electrons to convey:

I snipped a bunch, hope that's OK, because I only wanted to remark on
the "over the open internet" part.  

Me too. :)

See txt pic below (view in a fixed-width font)

Example: If the destination AU (using http://www.ietf.org/internet-drafts/draft-crocker-email-arch-04.txt terminology; AU=Administrative Unit)
is bigcompany.dom, and Relay2 is some MTA that just relays mail, and is under the control of the destination AU, then if a Sieve script running on Dest  encounters a 'refuse', and sends a 550 to Relay 2, if Relay 2 then generates a bounce, instead of sending a 550 to MSA, then Dest MUST NOT be considered compliant with 'refuse'. 

   +------------+                                    +-----------+
   | Originator |                                    | Recipient |
   +-----+------+                                    +-----------+
         |                                                 ^
         |                    Internet                     |
         |                    ___^___                      |
         V                   /       \                     |
     +---------+    +--------+       +---------+      +----+----+
     |         |    |        |       |         |      |         |
     | Source  +--->| MSA    +------>|  Relay2 +----> |  Dest   |
     |         |    |        |       |         |      |         |
     +----+----+    +--------+       +---------+      +---------+

                                 \_________Destination_AU__________/

Further example: If Dest was once reachable directly from the Internet and supported 'refuse', and was then protected by Relay2 then (depending on Relay2's abilities) Dest might no longer support 'refuse', through no fault of the coder of the software on Dest.  It would be the AU administrator's responsibility to support 'refuse', or stop claiming to support it.

BTW, fastmail handles *outgoing* mail like this - synchronously: If I try to send to foo(_at_)nonexistent(_dot_)dom, I an error  message pops up in my mail client (Thunderbird). (I've attached a .png screen shot, which may well not make it through to your screen.)  (This is far superior to getting a message in my inbox from the postmaster/mailer-daemon.)