Connecting to Exchange 2000 using Outlook 2003

I am running Windows XP Pro and have Office 2003. I am trying to setup Outlook to connect to an Exchange server at work. The Exchange server is running Windows 2000 Active Directory, and Exchange 2000. When I try to add the account, I enter the exchange server name, and my mailbox name. When I click "Check Name", it says "The Action Could Not Be Completed". I have even tried entering the IP of the Exchange server instead of just its name and I get the same error. Any ideas?