Step 1 : On your Unify Enterprise Edition dashboard, Go to "Orders >> Enter Phone Order". Learn more about phone orders here.
Step 2 : Upon creating the phone order, You will get a prompt asking 'Do you want to notify the customer?' If you choose in affirmative, the customer will be notified by email, about the order creation. Remember, you can choose to remember your action for every phone order that you create, after you check mark the 'Remember this action' box.