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Re: [Fwd: [Asrg] Verisign: All Your ...

2003-09-16 08:53:01
On Tue, 16 Sep 2003, Dean Anderson wrote:

On Tue, 16 Sep 2003, Bruce Campbell wrote:

On Tue, 16 Sep 2003, Edward Lewis wrote:

For these items of software to change from using a stateless method of
existence-verification with low overhead, to using a semi-stateless method
of existence-verification with high overhead, is something akin to the Y2K
bug in scope, albeit without all the hype.

The correct way to check for "domain existance" for email is to lookup an
MX record.

That would be the correct method as defined in RFC2821 would it?  The one
which specifies:

        5. Address Resolution and Mail Handling

                If no MX records are found, but an A RR is found, the A RR
                is treated as if it was associated with an implicit MX RR,
                with a preference of 0, pointing to that host.

Operationally, having one's not-low-overhead whois server being hit by
automated queries solely for existence-verification is a terrible state of
affairs.

One shouldn't be doing whois queries. One just wants to know if the domain
of the sender can receive email, back.

Yes.  If I receive an SMTP connection purporting to be from
'joebloe(_at_)ssdflvndslkvn(_dot_)com', and I follow the established standards 
for
seeing whether I can send mail back, I end up with 64.94.110.11 .  Ergo,
as far as that domain is concerned, it can receive mail back.

( This was covered at least 40 messages ago, do try to keep up ).

--==--
Bruce.