Wrote Thomas Fini Hansen <beast / system-tnt.dk>, on Wed, Jun 16, 2004 at 04:22:24AM +0900:
> On Wed, Jun 16, 2004 at 12:38:11AM +0900, Sam Roberts wrote:
> > >    Message-Id: <20040615020507.GA806 / ensemble.local.>
> > 
> > For what it's worth, it's an invalid Message ID. I don't know
> > who is generating it, either sendmail or mutt. Both might
> > claim that there is a bug in whatever call they are making
> > to the OS to get the host name, but its still wrong.
> 
> Uhm, not to be a RFC nazi, but what do you base that on? Ol' 822
> define Message-Id as addr-spec, which is pretty much an 'email
> address', which obviously ends in a domain name. And, say,
> 'ruby-lang.org.' is a valid domain name, as domains in fact are routed
> in '.' (much like the filesystem starts at /). Something you learn the
> hard way when fiddling with BIND zone files, forget the ending dot and
> find out that your alias to another domain name instead points at a
> subdomain of the same name.

The DNS specifications talk about DNS domain names ending in an
(explicit or implicit) dot, but it isn't allowed by RFC822.

RFC 822 says:

  domain      =  sub-domain *("." sub-domain)

And no, sub-domain is not allowed to include a "." character.  So,
addr-specs may "pretty much end in a DNS domain name", but not in "any
valid DNS domain name".

This may be a mismatch between the DNS and email address specifications,
but c'est la vie.

Cheers,
Sam

-- 
Sam Roberts <sroberts / certicom.com>