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Re: [ietf-smtp] Are A-label and U-label addresses supposed to be equivalent ?

2020-07-11 23:13:29
On Sat, 11 Jul 2020, John C Klensin wrote:
[ Are corresponding A-label and U-label addresses different mailboxes? ]

As distinct mailboxes, I think it would be within its rights to
do so.  I also think that, like the "user" and "UseR" local part
distinction, doing so would be fairly dumb and, if I were
implementing the MTA that <whatever> was going to use, I don't
think I'd go out of my way to make separating the two easy.

That's what I was thinking. But I was also thinking it might be different from upper/lower case mailboxes since, there is a defined mapping betwen A-labels and U-labels, and we already have at least one place, DNS lookups, where the MTA has to turn one into the other.

I'm doing a project for the UASG testing the EAI conformance of a bunch of mail software. It appears that Postfix treats A-label and U-label addresses differently, and Coremail may only accept the U-label and reject the A-label, although it's hard to tell because at the moment, its mail server for the 互联网.中国 domain doesn't accept anything.

MUA support leaves a lot to be desired, e.g. Roundcube webmail always turns the domain into A-labels, even if the mailbox is non-ASCII.



Coremail isn't accepting any mail at all for the 互联网.中国 domain. Telnet to port 25 and it says:

 554 IP<> is rejected: 0

Huh? What?
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