Message-ID: <01D6C7224936D211BA450000F805D53805421065@TOTO>
From: "Larry Osterman (Exchange)" <larryo@exchange.microsoft.com>
To: "Jeff Stephenson (Exchange)" <jeffstep@exchange.microsoft.com>,
        drums@cs.utk.edu
Subject: RE: editing status of 821bis, draft -10.
Date: Tue, 16 Feb 1999 12:19:59 -0800
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Personally I like it, it also gets around my "My cellular phone shouldn't
know how to do DNS/MX" problem...  However I suspect this will take some
careful wordsmithing to make it work right...


Larry Osterman
Sent from larryo-laptop.dns.microsoft.com running NT5 and Outlook 2000
and Exchange Server 5.5.  Please notify the sender of any difficulties


-----Original Message-----
From: Jeff Stephenson (Exchange) 
Sent: Tuesday, February 16, 1999 11:24 AM
To: drums@cs.utk.edu
Subject: RE: editing status of 821bis, draft -10.


> -----Original Message-----
> From: Larry Osterman (Exchange) [mailto:larryo@Exchange.Microsoft.com]
> Sent: Tuesday, February 16, 1999 10:20 AM
> 
> Like it or not, in the internet email sandbox everyone has to 
> play by the same rules.  At one time the rules were hard coded
> routing tables and store-and-forward.  Now the rules require
> that MTAs use MX resolution to route to the destination host.  
> 

I completely agree that when an MTA is operating in the Internet email
sandbox that it needs to follow the rules of MX resolution.  I think,
however, that from an engineering standpoint it might have been better to
separate the wire protocol for transfering mail (which has immense value in
and of itself) from the mechanism used to determine the next hop.  Don't get
me wrong, though - I'm not proposing that we try and rip apart 821bis to do
so at this late date.

What I'd suggest, though, is changing the wording to reflect what everyone
seems to be saying - that when you're a relay MTA on the Internet you MUST
do MX resolution, but otherwise you can determine the next hop any way you
want and still be 821bis compliant.  I think Philip Hazel's suggestion of "A
fully-conformant Internet MTA MUST conform to the SMTP specification AND
must support full DNS/MX
lookup" would do, as it makes the distinction between the wire protocol
(which most folks think of when you say "SMTP") and the next hop decision.

-- jeff