I have added a new Contact Us page but it's not working and says
E-mail has not been setup properly. Please add your contact e-mail!
Please help... From where do I can configure it properly? Here is the link http://designstutorial.com/?page_id=93
Go to your WP admin section, and under Apperance, there should be a Theme Options section, see if there is a place to set the email there.
If not, see if the developer has provided some documentation.