knottyrope is right!
What setup are you using in Outlook? That surely isn't a MAPI connection. If you create the account using the Microsoft Exchange choice, then you won't set a "Check every" timeout. But MAPI in cache mode does check every 2 minutes or so - it doesn't maintain a connection like the non-cache MAPI.
Also, depending on what protocol you are using - you are downloading the mail to the laptop. The Exchange server doesn't change the state of the mail on the Exchange just because you downloaded it. Also, changes you make locally won't be sent to the Exchange server until the next check - and even then it may not send read/unread status.
It sounds like Exchange and Blackberry are working properly, but the laptop is configured wrong.