Kari Hurtta wrote, answering either Pete Resnick or Charles Lindsay:
But if 2822-bis is prepared to go further than that, then it is fine
with me. The only question is whether people ever (or ever need to)
use <quoted-string>s in <msg-id>s. I looked in all the news articles
and
emails on my computer and found no example of it, but my sample is
far too small. So has anyone else seen that in the wild?
At least on my archive folder have some:
$ egrep ^Message-ID: elm-mail-backup | fgrep '"'
Message-ID: <"xlink100.x.795:21.07.96.17.56.16"@xlink.net>
...
$
These archived messages seems to be from year 1996
One of formail, procmail and smartlist also generated message-ids
containing quoted-string around that time. AFAICR the format was
"word.word.word"@hostname.
I've looked at around 100,000 recent message-ids and found none that
required quoted-string.
Arnt