Multiple Exchange Environment and Routing Mail

I have two forests with Exchange that are able to send email with other public domains fine, but are unable to send email to eachother.  I will get a delayed delivery notice and then finnaly I get back the following...

Generating server: EXCH01.xx.net

cexline@netiqdemo.com
#550 4.4.7 QUEUE.Expired; message expired ##

Original message headers:

Received: from EXCH02.exline.net ([fe80::cbd:db19:d7d1:274c]) by
 EXCH01.exline.net ([fe80::f4c2:355a:9b9e:955d%15]) with mapi id
 14.01.0270.001; Tue, 21 Dec 2010 12:19:08 -0700
From: Christopher Exline <chris@xx.net>
To: "cexline@netiqdemo.com" <cexline@xx.com>
Subject: test cexline@xx.com
Thread-Topic: test cexline@xx.com
Thread-Index: AcuhRN6i7OqlV0XaSPWqraYMdywLKA==
Date: Tue, 21 Dec 2010 19:19:07 +0000
Message-ID: <B061E9B2BC43924D88A8ECEB79DAC70B1EB85ED0@EXCH02.xx.net>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [68.2.171.181]
Content-Type: multipart/alternative;
      boundary="_000_B061E9B2BC43924D88A8ECEB79DAC70B1EB85ED0EXCH02exlinenet_"
MIME-Version: 1.0

What I have tried already.
1.  I have tried the Exchange Remote Connectivity Analyser (https://www.testexchangeconnectivity.com/) and everything looks fine on both my domains.

There appears to be an Exchange setting I am missing here to get these forests to see eachother on the LAN as friendly and pass messages.  Any help is much apprediated.