Compu$erve RFC 1123 5.3.3 violation

Sun Nov 17 09:56:17 UTC 1996

Paul A Vixie <paul at vix.com> said:
> This:
   [deleted]
> ...is NOT a variance from RFC1123 or any other specification.

That's true (as far as it goes), and I certainly don't see that bouncing
mail with a "mailbox is full" error is a violation of RFC1123 section
5.3.3. 

But the following piece of evidence was not mentioned before:

        compuserve.com.           MX    10 mailgate.compuserve.com.

That MX, in conjunction with the CNAME (which was mentioned before):

        mailgate.compuserve.com.  CNAME mx3.compuserve.com.

adds up to a violation of RFC 1034 section 3.6.2:

        "Domain names in RRs which point at another name should always
        point at the primary name and not the alias."

(which esentially means "If a name appears on the left hand side of a
CNAME record then that name should not also appear on the right hand side
of any other record"). 

> It is
> completely appropriate for a mail domain to be a CNAME pointing at a
> handful of A's.  It's not ok to _advertise_ one of these, as for example
> in an exported "From:" header,

I am not sure that my reading of RFC 1123 section 5.2.2 awould support
you there.  But anyway, the "compuserve.com" domain *does* get advertised
in "From:" headers, so there is clearly a problem.

--apb (Alan Barrett)