Exchange remote admin permission problem

Hi,

We are using Exchange 5.5. I wanted to be able to connect from my desk to do simple mailbox editing to peoples address info. I installed the microsoft exchange administrator tool from the cd. It launches and asks to select a server. Once I select our exchange server I receive the message “do not have proper permissions required to complete operation”. I have admin rights so Im not sure what permissions and where I need to apply them. Help please.