Subject: Re: (ngtrans) Re: ipv6-smtp-requirement comments?

From: [email-masked]
Date: Mon, 05 Nov 2001 15:31:20 +0900

>>I think we're talking past each other. Let me try again, with a clearer,
>>better question:
>>
>>RFC1893 lists a number of status codes to be used when a message cannot be
>>delivered. If the target domain exists, but mail cannot be sent there due
>>to protocol mismatch, which RFC1893 code should the SMTP sender use? Or
>>should an additional status code be defined?
>	hmm now I see what you are talking about.  my guess is 444
>	(persistent transient/unable to route), but i'm not 100% sure.

	thought about this again, and found that the following two cases
	should raise the same error code.  what is the commonly-practiced
	error code for the former case?  then, we know the error code for the
	latter case.

	(let us assume that the sender is an IPv4-only MTA)

example.com.		IN MX 1 mx1.example.org.
; no A for mx1.example.org

example.com.		IN MX 1 mx1.example.org.
mx1.example.org.	IN AAAA	3ffe:501:ffff::1

itojun

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From: Arnt Gulbrandsen <[email-masked]>
Date: Mon, 5 Nov 2001 15:21:17 +0100

[email-masked]
> 	error code for the former case?  then, we know the error code for the

Then the error code is "the same as...". Ie. SMTP client authors should be
instructed to treat the new error case the same way as they treat the
older one.

--Arnt

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From: [email-masked]
Date: Tue, 06 Nov 2001 08:42:14 +0900

>instructed to treat the new error case the same way as they treat the

	are you saying there's no clear documentation on current error code
	handling, and i should leave it equally unclear?  what is the exact
	code you would use in this case?

itojun