Thank you for your reply. I am not trying to argue for or against the validity
of such domain names or question RFC in any respect. Just want to get some
feeling from people in this list how practically important a support for such
domain names can be.
BTW, I can imagine something like god(_at_)heaven where 'heaven' is FQDN in a
given DNS infrastructure. I.e. there is only one heaven in the universe and it
is probably not a subordinate of any other entity. My understanding is that DNS
is flexible enough to support this. What about practical examples?
Thanks,
Yuri Inglikov
-----Original Message-----
From: Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu
[mailto:Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu]
Sent: Friday, April 21, 2006 11:43 PM
To: Yuri Inglikov
Cc: ietf-smtp(_at_)imc(_dot_)org
Subject: Re: domain name definition in RFC2821
On Fri, 21 Apr 2006 21:44:03 PDT, Yuri Inglikov said:
There appears to be some disconnect between ABNF syntax and a prose. I.e. i t
appears that ABNF requires at least 2 sub-domain parts, while prose discu sses
"one or more dot-separated components". Which one is "more correct" an d any
scenario when a single-component domain name can be valid / useful in modern
SMTP?
Can you give an example of a "single-component domain name" that would *not*
be flagged as a failure to canonalize to a FQDN?
Are there any e-mail addresses that *work* (or even could *potentially* work)
of the form 'userid(_at_)com' or 'userid(_at_)net' or
'some(_dot_)full(_dot_)name(_at_)to' or anything
else like that?
(And even if you require 2 components, it's traditionally been ugly. There
were a *lot* of university computing centers and comp-sci departments that were
quite surprised when all the addresses of the form
'userid(_at_)server(_dot_)cs' or
'userid(_at_)server(_dot_)cc' were no longer recognized as a shorthand for
'server.cs.foo.edu' or 'server.cc.bar.edu'. And some of us were around for
when British schools leaked reverse-order domain names, and
'user(_at_)uk(_dot_)ac(_dot_)FOO(_dot_)cs'
went to another country rather than to U of Foo's CS dept...)