Internal IP showing in headers of emails to external IP's?

[thabrock]

Can you take a look at this header and tell me if we are broadcasting our internal IP to our email recipients and tell me how we can fix it if we are.

This is the header from an email I sent from my internal email to my external email.

Header info:

67.224.xx.xx = Our public IP
10.xx.xx.10 = Our internal server IP address
10.xx.xx.110 = My computer

ACTUAL HEADER:

Delivered-To: user@external_address.com
Received: by 10.224.10.202 with SMTP id q10cs108685qaq;
Tue, 13 Apr 2010 10:18:07 -0700 (PDT)
Received: by 10.141.4.10 with SMTP id g10mr5759996rvi.179.1271179086455;
Tue, 13 Apr 2010 10:18:06 -0700 (PDT)
Return-Path: <user@ourdomain.com>
Received: from server_name.ourdomain.com (server_name.ourdomain.com [67.224.xx.xx])
by mx.google.com with ESMTP id 11si5868475pzk.131.2010.04.13.10.18.05;
Tue, 13 Apr 2010 10:18:06 -0700 (PDT)
Received-SPF: pass (google.com: best guess record for domain of user@ourdomain.com designates 67.224.xx.xx as permitted sender) client-ip=67.224.xx.xx;
Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of user@ourdomain.com designates 67.224.xx.xx as permitted sender) smtp.mail=user@ourdomain.com
Received: from 10.xx.xx.110 ([10.xx.xx.110]) by server_name.ourdomain.com([10.xx.xx.10]) with Microsoft Exchange Server HTTP-DAV ;
Tue, 13 Apr 2010 17:18:05 +0000
User-Agent: Microsoft-Entourage/12.24.0.100205
Date: Tue, 13 Apr 2010 10:18:04 -0700
Subject: Blah blah blah
From: <user@ourdomain.com>

 

[58sniper]

Yes. What's the concern?

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[ShackDaddy]

I don't think knowledge of internal IP's is as much of a security flag as it was considered in the past. Even emails from Microsoft employees still reveal internal IP addressing info.

Dave Shackelford MVP
ThirdTier.net
TrainSignal.com

 

[thabrock]

Thanks for the responses guys! I actually wasn't as concerned about the security as I was about if this would effect ReverseDNS checks.

I knwo that our server says HELO or EHLO
I am "server_name.ourdomain.com"
I am at IP Address "67.224.xx.xx"

The receiving server then does a ReverseDNS check to make sure that IP Address "67.224.xx.xx" does resolve back to "server_name.ourdomain.com".

I just want to make sure that our internal IP adress is not mucking this up - we have been getting our emails to Earthlink users bounced back as spam and can't figure out why. We are not on any blacklist they use and our ReverseDNS seems fine to me.