Problem forwarding mail using a contact in AD

We are currently forwarding mail to one of our user's outside mail accounts using an AD Contact.  This works fine until someone sends an e-mail from a yahoo address to this person.  At this point, the outside mail server rejects the message.  I thought for a while that it might be how thier server accepts 8 bit mime messages, but they are able to recieve messages directly from a yahoo sender, so I don't think that is it.
We also have a Barracuda SPAM firewall in place that scans all inbound e-mail.
Destination address: info@brianfelsen.com
Forwarding address:billyg@discmakers.com


@@@Here is the bounce back message that a yahoo sender would recieve
From: postmaster@discmakers.com Add to Address Book Add Mobile Alert
To: popomus@yahoo.com
Date: Tue, 14 Mar 2006 14:52:50 -0500
Subject: Delivery Status Notification (Failure)

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed.

info@brianfelsen.com

Message/delivery-status

Reporting-MTA: dns;dmexchange2.discmaker.com
Received-From-MTA: dns;barracuda.discmakers.com
Arrival-Date: Tue, 14 Mar 2006 14:52:47 -0500

Final-Recipient: rfc822;info@brianfelsen.com
Action: failed
Status: 5.6.1
Diagnostic-Code: smtp;554 5.6.1 Body type not supported by Remote Host
X-Display-Name: Felsen, Brian

@@@Here is a message that is from a yahoo address that goes through our Forward, to a yahoo address
X-Apparently-To: dmtest4felsen@yahoo.com via 209.191.87.60; Thu, 20 Apr 2006 10:30:32 -0700
X-Originating-IP: [209.204.108.18]
Return-Path:
Authentication-Results: mta265.mail.mud.yahoo.com from=yahoo.com; domainkeys=pass (ok)
Received: from 209.204.108.18 (EHLO dmexchange2.discmaker.com) (209.204.108.18) by mta265.mail.mud.yahoo.com with SMTP; Thu, 20 Apr 2006 10:30:32 -0700
Received: from barracuda.discmaker.com ([192.168.10.160]) by dmexchange2.discmaker.com with Microsoft SMTPSVC(5.0.2195.6713); Thu, 20 Apr 2006 13:21:25 -0400
X-ASG-Debug-ID: 1145553675-21656-62-0
X-Barracuda-URL: http://192.168.10.160:8000/cgi-bin/mark.cgi 
Received: from web37415.mail.mud.yahoo.com (web37415.mail.mud.yahoo.com [209.191.87.68]) by barracuda.discmaker.com (Spam Firewall) with SMTP id E4E45C56DE for ; Thu, 20 Apr 2006 13:21:15 -0400 (EDT)
Received: (qmail 67398 invoked by uid 60001); 20 Apr 2006 17:21:15 -0000
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=t6IwRCU2RwUAsRJFNZ+9JRGwbs/VKVR4ShxvbWNJWqYSRICCum3RNDgiv8BWtRIvjVmOmM2NiL8mbBvwpeW52DqkUudnUQHeYQsdjSZwuvCpObubyHMAvQuip635MPQ1C2ST9ZuNPlJN2NCH1znNWtYGfWBru1lGK9xi9LQrgRE= ;
Message-ID:
Received: from [209.204.108.18] by web37415.mail.mud.yahoo.com via HTTP; Thu, 20 Apr 2006 10:21:15 PDT
Date: Thu, 20 Apr 2006 10:21:15 -0700 (PDT)
From: "me me"
X-ASG-Orig-Subj: 1:20 from yahoo via fwd
Subject: 1:20 from yahoo via fwd
To: billyg@discmakers.com
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="0-1001472536-1145553675=:66970"
Content-Transfer-Encoding: 8bit
X-Barracuda-Bayes: INNOCENT GLOBAL 0.0032 1.0000 -1.9998
X-Virus-Scanned: by Barracuda Spam Firewall at discmaker.com
X-Barracuda-Spam-Score: -2.00
X-Barracuda-Spam-Status: No, SCORE=-2.00 using global scores of TAG_LEVEL=1.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=3.0 tests=
X-Barracuda-Spam-Report: Code version 3.02, rules version 3.0.11130 Rule breakdown below pts rule name description ---- ---------------------- --------------------------------------------------
Return-Path: dmtest4felsen@yahoo.com
X-OriginalArrivalTime: 20 Apr 2006 17:21:25.0794 (UTC) FILETIME=[DA5F8020:01C6649E]
Content-Length: 682

@@@Here is the header from a message that goes directly from a yahoo address to the outside domain's mail server
Return-path:
Envelope-to: info@brianfelsen.com
Delivery-date: Wed, 15 Mar 2006 09:45:53 -0800
Received: from brianf3 by kupio.lunarpages.com with local-bsmtp (Exim 4.52)
id 1FJa4G-0000T4-56
for info@brianfelsen.com; Wed, 15 Mar 2006 09:45:53 -0800
X-Spam-Level:
X-Spam-Status: No, score=-2.2 required=5.0 tests=ADDRESS_IN_SUBJECT,AWL,
BAYES_00,HTML_50_60,HTML_MESSAGE autolearn=ham version=3.1.1
X-Spam-Checker-Version: SpamAssassin 3.1.1 (2006-03-10) on
kupio.lunarpages.com
Received: from [216.40.36.58] (helo=c1m25.emaildefenseservice.com)
by kupio.lunarpages.com with smtp (Exim 4.52)
id 1FJa4F-0000St-Sg
for info@brianfelsen.com; Wed, 15 Mar 2006 09:45:52 -0800
Received: from web50913.mail.yahoo.com [206.190.39.81] (HELO
web50913.mail.yahoo.com)
by c1m25.emaildefenseservice.com (mxl_mta-1.3.8-10p10) with SMTP id
dc258144.926.092.c1m25;
Wed, 15 Mar 2006 12:45:49 -0500 (EST)
Received: (qmail 87250 invoked by uid 60001); 15 Mar 2006 17:45:48 -0000
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
s=s1024; d=yahoo.com;

h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content
-Transfer-Encoding;

b=2IbCqhdqe754eXMm3yuOdVL4g9tls5tNtQJ60wUdgmdMDblxn7RrbS+xTYB02jct3K3GJtQDqR
HXCPu1UR5I7PKogpWV1T/O9wGpjto9o+z/ABExkv9TBVkG/px+E+50cVXW3ud8xNpGf3opJSiXSe
vPHM2t7tJyQ0+oj9Iobfw= ;
Message-ID:
Received: from [69.169.1.246] by web50913.mail.yahoo.com via HTTP; Wed, 15
Mar 2006 09:45:48 PST
Date: Wed, 15 Mar 2006 09:45:48 -0800 (PST)
From: Elif Savas Felsen
Subject: yahoo to info@brianfelsen.com
To: info@brianfelsen.com
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="0-311179464-1142444748=:86773"
Content-Transfer-Encoding: 8bit
X-Spam: [F=0.0100000000; heur=0.500(1500); stat=0.010;
spamtraq-heur=0.500(2006031501)]
X-MAIL-FROM:
X-SOURCE-IP: [206.190.39.81]