Outlook 2003 multiple emails

I am running a small network at my office (4 computers). My computer has 2000pro and another has XP pro. I have installed Office 2003 with outlook. mine works fine, but the XP machine will download the same email every time its restarted until its deleted off the server (6 days after receipt). Have reinstalled outlook (several times) and recreated email account and it is still downloading email over and over. Can any help?