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Re: Dreaming about replacements (was IDN (was Did anyone tellMicrosoft ye

2002-05-07 07:44:34


Paul Smith wrote:

At 10:43 04/05/2002 -0500, Eric A. Hall wrote:
DSNs with NOTIFY=SUCCESS are an obvious example. The only thing I care
about is that delivery succeeds, meaning that this is a negotation
between the originator and the delivery server.

Well, the OBVIOUS answer to that, is to take the DSN information out of
the envelope and put it into the header.

Couple of problems with that approach. First is that delivery servers
would have to start poking through the headers of all incoming messages
just to find out if the message required a delivery receipt. That's a lot
of work in contrast to simply being told to do so, as with the current
model of envelope extensions. Secondarily, some of the recipient-specific
fields can't be implemented as shared header fields, as they would affect
all of the recipients. Which of the dozen Original-Recipient header fields
is for me?


does this mean that all MUAs/MTAs would have to support BOTH message
format structures (or just the existing format..) for the forseeable
future?

Mail readers wouldn't have to support two mailbox formats. It should be
feasible to convert 822 mails into the new format pretty simply: dump the
envelope into the envblob, dump the header section into the hdrblob, and
tag it as a legacy message. The legacy body parts should render same.

The transition would require that delivery servers be capable of
performing conversions based on the mailbox format in case a reader is
using a legacy mail-store format. The originator or submission server (in
those cases where they are the same process) would also need to perform
any auto-conversion of outbound messages which failed due to transfer
failure (and which were identifiable as such, which the enhanced envelope
should allow for).

-- 
Eric A. Hall                                        http://www.ehsco.com/
Internet Core Protocols          http://www.oreilly.com/catalog/coreprot/