Failed to send Emails from CRM-2011

Hi Guys,

I am unable to send emails from CRM. however, I have installed and configured Outlook for CRM 2011 correctly as well as did configuration insude the CRM User Settings & Email Settings but still the status is pending send and showing a message "This message has not yet been submitted for delivery. For more information, see help".

Can anyone tell me which part I am missing?

Thanks