Hello, Here is my scenario. I currently have some users in a trusted domain that are using a 2008 terminal server. On this server I want them to be able to access a mailbox in my domain on an Exchange 2003 server. I have given the users from the trusted domain Full Mailbox Access as well as Associated External Account rights to the mailbox on my domain. When I attempt to set up a profile in Outlook 2007 on the terminal server, they are prompted for credentials, and even if I enter credentials I cannot gain access. Anyone have any ideas? Thanks so much! Travis EDIT - I forgot to mention, these are both Native Mode 2003 domains.

Hi, I am suspecting the permission was not setup correctly. Please double check and refer to: http://technet.microsoft.com/en-us/library/bb124779(v=exchg.65).aspx http://www.msexchange.org/tutorials/understanding-external-associated-account-windows-server-2003-exchange-2003.htmlFiona Liao TechNet Community Support

Can we setup a new test mailbox and assigned the associate external account and Full access permission to any user account in the other forest. Make sure the permission inheritance is in place... Lets see if the user can access the mailbox Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Hasnain Shaikh| My blogs: http://messagingserversupport.com

The best way is to configure linked mailboxes. See the second answer in this thread and the links in the first answer. How to set up linked mailbox in exchange 2003 http://social.technet.microsoft.com/Forums/en-US/exchangesvrdeploy/thread/4b5b3d6b-416a-4368-bae2-c8ec4768d8ad/ MCTS: Messaging | MCSE: S+M