Re: get personal info from an email address

From: Frank Slootweg (this_at_ddress.is.invalid)
Date: 01/14/04 

Date: 14 Jan 2004 11:04:07 GMT

JWMeritt <jwmeritt@aol.com> wrote:
> Frank Slootweg asked:
>> Did you read/understand my example (which you snipped)? :
>
> Yup. Very well. Perhaps even better than you did.

  I don't think so, but read on.

>> I.e. you only have the information "user@domain1.tld1" and you have
>>*no way* of *knowing* any part of "mailserver.domain2.tld2".
>
> And, of course, the domain name server lies when it reveals the MX record
> contents. Wait! It can't or it will not be able to receive mail.

  The domain server will tell you where mail will be *sent to*, not were
mail is *sent from*. The to and from location do not have to have *any*
relation. And then there is mail forwarding, so what you *think* is the
to-address, isn't.

>> I think that you think that a mailserver has to be in the same
>>domain as that in the From: line, but many mailservers do not have such
>>a requirement and the SMTP standard does not have such a requirement
>
> You think incorrectly.

  If you mean that I do not know what you think, then that is quite
possible, so please enlighten us/me, instead of giving vague and
unspecific answers. I.e. *exactly* what do *you* think can be derived
from the information "user@domain1.tld1"? For example what *exactly* can
you derive from my address <user>@web.de?

  If OTOH you think that mailservers *do* have to be in the same domain
as those in the From: line, then this little log will show you that you
are mistaken (the "NOYB" part is exactly that):

> Received: from hnexfe07.hetnet.nl ([10.94.9.30]) by HNEXVS03.HETNET.LOCAL with Microsoft SMTPSVC(5.0.2172.1);
> Tue, 13 Jan 2004 15:28:45 +0100
> Received: from smtp6.wanadoo.nl ([194.134.35.177]) by hnexfe07.hetnet.nl with Microsoft SMTPSVC(5.0.2195.5329);
> Tue, 13 Jan 2004 15:28:44 +0100
> Received: from ipc1fs02 (unknown [83.117.108.250])
> by smtp6.wanadoo.nl (Postfix) with ESMTP id B7E2877C49
> for <NOYB@hetnet.nl>; Tue, 13 Jan 2004 15:28:42 +0100 (CET)
> Message-ID: <00a901c3d9e1$89bfe730$647ba8c0@neth.hp.com>
> From: "Frank Slootweg" <NOYB@web.de>
> To: "Frank (HetNet)" <NOYB@hetnet.nl>
> Subject: Test to check first mailserver.
> Date: Tue, 13 Jan 2004 15:28:33 +0100
> MIME-Version: 1.0
> Content-Type: text/plain;
> charset="iso-8859-1"
> Content-Transfer-Encoding: 7bit
> X-Priority: 3
> X-MSMail-Priority: Normal
> X-Mailer: Microsoft Outlook Express 6.00.2600.0000
> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
> X-Antivirus: avast! (VPS 08/01/2004), Outbound message
> X-Antivirus-Status: Clean
> Return-Path: NOYB@web.de
> X-OriginalArrivalTime: 13 Jan 2004 14:28:44.0842 (UTC) FILETIME=[8CBAB0A0:01C3D9E1]
> X-Antivirus: avast! (VPS 08/01/2004), Inbound message
> X-Antivirus-Status: Clean
>
> Is probably wanadoo.nl, not web.de.