[ietf-smtp] Should we update an RFC if people refuse to implement parts of it ?

"John R. Levine" <johnl@iecc.com> Mon, 24 May 2021 23:06 UTC

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Date: 24 May 2021 19:05:53 -0400
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From: "John R. Levine" <johnl@iecc.com>
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Subject: [ietf-smtp] Should we update an RFC if people refuse to implement parts of it ?
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I've been doing some EAI tests.  RFC 6531 section 3.7.3 says that domain 
names in trace headers SHOULD all be U-labels.  In practice, everyone uses 
A-labels for reasons that are not absurd.  The FROM clause has the name 
from the EHLO command which has to be sent as A-labels, and it's quite 
plausible to have a message where the message itself is entirely ASCII, 
sent to a UTF-8 address, which then could be forwarded to an ASCII address 
except that it has those U-labels in the trace header which would have to 
be downgraded.  I've talked to a couple of MTA maintainers who have told 
me forget it, that's silly, not doing that.

In a situation like this, would it make sense in a future update to the 
RFC to adjust the advice to the reality?

John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly