Hope I can explain this right, but I'll give it a shot.

Just got my first Mac and have installed and setup Outlook 2011 to connect to my Exchange 2007 server.  When I open Outlook, it connects to the server and downloads my e-mails.  The problem is if I do something within Outlook (such as read messages, delete them, move them to another folder, etc), those changes never get reflected back on the server.  So if I were to look at my e-mail on my phone or my PC, all my e-mails appear as new and unread. 

Any ideas as to what is causing this?