One Outlook Profile is all that is needed.  Have you tried recreating the
Outlook Profile?

Hello,

Thank you for your post. My name is Robbin Meng, and it is my pleasure to
work with you on this issue!

Please allow me to confirm that my understandings are correct. As I
understand it, the issue is:
                           
You have configured  Exchange server 2007 to use Outlook Anywhere, the
users get prompted for the domain user login even after they logon to the
domain internally. You would like to know if there is any way for outlook
anywhere to defer to the windows login so that it will not prompt for user
credential when logon internally.

If I have misunderstood your concerns please feel free to let me know.

Based on experience and research, I'd like to provide you with the
following suggestions:

Suggestion 1: As John indicated, if the issue only occurs to this user, we
may create a new Outlook profile to test again.

How to create a new e-mail profile in Outlook 2007 and in Outlook 2003
http://support.microsoft.com/kb/829918/en-us

Suggestion 2: Check the Authentication mode of Outlook Anywhere via
Exchange Management Console

a. To use the Exchange Management Console to enable Outlook Anywhere
1.    In the console tree, expand Server Configuration, and then click Client
Access.
2.    In the action pane, click Enable Outlook Anywhere.
3.    In the Enable Outlook Anywhere Wizard, in the box under External host
name, type the external host name for your organization.
4.    Select an available external authentication method. Please select NTLM
authentication (NOT Basic authentication).
5.    If you are using an SSL accelerator and you want to do SSL offloading,
select the check box next to Allow secure channel (SSL) offloading.
Note:
Do not use this option unless you are sure that you have an SSL accelerator
that can handle SSL offloading. If you do not have an SSL accelerator that
can handle SSL offloading and you select this option, Outlook Anywhere will
not function correctly.
6.    Click Enable to apply these settings and enable Outlook Anywhere.
7.    Click Finish to close the Enable Outlook Anywhere Wizard.
8.   
b.  To use the Exchange Management Shell to enable Outlook Anywhere
1.    Run the following command:

Enable-OutlookAnywhere -Server:'ServerName'
-ExternalHostName:'ExternalHostName'-ExternalAuthenticationMethod:'Basic'
-SSLOffloading:$false

Suggestion 3: However, if the issue persists, to work around this problem,
you can add the DisableCredUI registry entry. To do this, follow these
steps:

1.     Click Start, click Run, type regedit , and then click OK.
2.     Locate and then click the following registry subkey:
HKEY_CURRENT_USERS\Software\Microsoft\Office\11.0\Outlook\RPC
Note If the RPC subkey does not exist, you have to create it.
3.     Create the following registry entry:

o    Name: DisableCredUI
o    Type: REG_DWORD
o    Value: 1

When you set the value to 1, the operating system credentials UI is
disabled. The Outlook credentials UI will be used instead.

Hope this helps. Also, if you have any questions or concerns, please do not
hesitate to let me know.

Thank you for your time and cooperation.

Best regards,

Robbin Meng(MSFT)

Microsoft CSS Online Newsgroup Support

Get Secure! - www.microsoft.com/security

=====================================================

This posting is provided "AS IS" with no warranties, and confers no rights.