Email using domainkeys and spf

Gabriel Gunderson gabe at gundy.org
Sat Oct 1 11:14:39 MDT 2005


On Sat, 2005-10-01 at 08:35 -0500, Matthew Frederico wrote:
> Hope that helps!

I think it does.  It gets me looking in the right direction.  I'm going
to attach a bit of the mail that got sorted into yahoo's bulk bin to see
if anyone can spot anything that looks problematic.

The set up is as follows:

Exchange server sits on a private subnet
(riddler.GoodCompany.local 10.0.0.40).

Mail gets relayed through a host running Postfix on the network's border
(mail.GoodCompany.tld 10.0.0.1 and public IP).  It does spam and virus
scanning (both directions).

mail.GoodCompany.tld is listed as the first MX for GoodCompany.tld

Not that is seems to matter but this TXT record is also in DNS:
"v=spf1 a mx ptr ?all"

The public IP address has been used by this company for a long time (5+
years) but not for sending mail until now.  The host
(mail.GoodCompany.tld) resolves to the public IP and the IP resolves
back to the host name.

Thanks for your help tracking down this mystery.

Gabe
-------------- next part --------------
X-Apparently-To:  UserAtYahoo at yahoo.com via web50002.mail.yahoo.com; Fri, 30 Sep 2005 12:47:54 -0700

X-YahooFilteredBulk: "mail.GoodCompany.tld (IP)"

X-Originating-IP: ["mail.GoodCompany.tld (IP)"]

Return-Path: <SomeUser at GoodCompany.tld>

Authentication-Results: mta150.mail.mud.yahoo.com from=GoodCompany.tld; domainkeys=neutral (no sig)

Received: from "mail.GoodCompany.tld (IP)" (EHLO mail.GoodCompany.tld) ("mail.GoodCompany.tld (IP)") by mta150.mail.mud.yahoo.com with SMTP; Fri, 30 Sep 2005 12:47:54 -0700

Received: from localhost (mail.GoodCompany.tld [127.0.0.1]) by mail.GoodCompany.tld (Postfix) with ESMTP id BD9AD586B1 for < UserAtYahoo at yahoo.com>; Fri, 30 Sep 2005 13:47:52 -0600 (MDT)

Received: from mail.GoodCompany.tld ([127.0.0.1]) by localhost (mail.GoodCompany.tld [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 09911-01 for < UserAtYahoo at yahoo.com>; Fri, 30 Sep 2005 13:47:52 -0600 (MDT)

Received: from riddler.GoodCompany.local (unknown [10.0.1.42]) by mail.GoodCompany.tld (Postfix) with ESMTP id 79C21584B8 for < UserAtYahoo at yahoo.com>; Fri, 30 Sep 2005 13:47:52 -0600 (MDT)


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