Cannot connect to Exchange server from Outlook client on Windows 2003 Server
 

This is sort of a repost as I have yet to find an answer to this issue.
Search the KB's, googled to error message and have been led in the right
direction but still no resolution. Here's my problem.

When using using Outlook from a Windows 2003 Server desktop, an RDP or ICA
connection I cannot use the Outlook client. I have remote users who connect
using Citrix. They logon to the Citrix server desktop (Windows 2003 Server)
and use Outlook from there. They can also use Outlook from within Citrix as
it is a Published Application. I know some of you are going to suggest why
don't they use OWA but let's not get into that. I can log onto any
workstation here in the office and connect to the Exchange server and open
their Outlook. What I and they cannot do now is after I create a new profile
on the Windows 2003 server desktop locally or from a RDP or ICA remote
connection. Open Outlook I am always getting this error message..........

"Cannot start Microsoft Office Outlook. Unable to open the Outlook window.
The set of folders could not be opened. The connection to the Microsoft
Exchange Server is unavailable. Outlook must be online or connected to
complete this action".

OK so here is the confusing problem. After I attempt to use Outlook and get
this error message I check my Event Viewer Application log. Everytime it
creates 2 entries. The first one is always...

Type: Information
Source: Outlook
Category: None
Event ID: 26
Description: Connection to the Microsoft Exchange Server has been lost.
Outlook will restore the connection when possible.

The second one it reports immediately after is always..

Type: Information
Source: Outlook
Category: None
Event ID: 26
Description: Connection to the Microsoft Exchange Server has been restored.

From my earlier posting I did receive some helpful hints on what could be
causing the problems. I'm leaning torwards ISA but cannot figure out which
rule or what rule I need to create to resolve the problem. Please any
suggestions or advice if greatly appreciated.