279827 Active Directory/Win2k3 Expert

Looking for a Active Directory / Win2k3 expert to help troubleshoot the set up of a mailbox. Mailbox has been setup with ISP and an account created within Active Directory. However, when we log in using that account into the domain and setup outlook for access it says that it cannot find the pop3 server. On that same machine if we login using an existing user then we are able to setup the mailbox within outlook and receive/send email. I've checked the obvious things and require some assistance getting the mailbox configured for a particular user. It probably is a problem with the account in Active Directory.