Microsoft Outlook 2010 – Cannot Log In

Hi All,
I just want to ask what would be the reason why I cannot access my Microsoft Outlook 2010? I am always receiving an error message saying,
"Check to make sure you are connected to the network and are using the proper server and mailbox name. The connection to the Microsoft Exchange Server is unavailable. The outlook must be online or connected to complete this action."
I already checked my Internet Connection and there is no problem with it. Please help me to resolve this issue.
Thank you so much!
– Ryan C.
