Outlook 2003 Problem: Received emails show up in colleague’s inboxes

I am having problems setting up an email account for my new job. I am able to send emails, however, emails that are sent to my address are put into inboxes of everyone in the sales staff. I have tried to set up rules that filter any emails with my name in the recipient box into my inbox, but thid did not work. Can anyone give me some pointers?