There are 3 ways to close a call:
1. From the List All screen, you will see a red lock image. By clicking this, it will prompt to close that call.
2. From the List All screen, if you click on the subject, it will show you the details of the call and a "Close" button appears.
3. While modifying a call, you can select a radio button which emails the customer and closes the call in one step.
For method #1 or #2, it will take you to the "Are you sure you want to close this call" page. If you click on "Click here to close call without sending email", it will do just that. If you click on the Close button, it will close the call and send out the final email notice to the customer.