Unable to use Mac for Exchange 2010 client!

I'm facing this strange problem using Exchange 2010 on my Mac with both mail.app and outlook 2011. We have Exchange 2010 server. But everything works perfectly on iOS. Every time I try to connect I get following error

Outlook cannot connect to the Exchange server. -18597 

Can anyone help me with this please?


Error -18597 means Outlook is getting an HTTP Error 403 from the Exchange server. You probably have incorrect credentials or something strange on the Exchange server. Check the logs on the server for more details.