Need passwrod when use Oulook 2010 and Exchange 2010

I'm using Outlook 2010 and Exchange 2010. In outlook, I set type : Microsoft Exchange. When I open outlook, I always receive message : " Need password". And I check tab " Send /Receive , I see : " Type Exchange Password & Connect"

If I set type" POP" , I don't receive message : " Need password".

Please help me fix this problem.

Thank you very much!