The blocks (left margin) in your Moodle course can be customized (moved up and down in the queue as well as added or subtracted).  If you discover a block is missing (e.g., the Quickmail, Accessibility, or Calendar block), you can easily add it to your course.

1. In the upper right corner of your course, click "Turn editing on."
   
   
   
   
2. Scroll down to the bottom of the blocks (left margin), and from the drop-down menu in the "Add a block" block, select the block you want to add.
   
   Tip: Type the beginning letter of any block to quickly navigate the list alphabetically. For example, type "q" to find QuickMail.
   
   
   
   
3. Wait a moment for the page to refresh (reload) and you will see the block added to the left side.