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<10.12.1.170> is rejected: 0
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