Email, Mozilla Thunderbird, How to get the folder pane/view back
If you can no longer see the folders that normally are in the left side of the screen, the most likely cause is that the message view has inadvertently covered it up. To get it back do the following:
The pane showing my folders disappeared. How do I get my folders back?
1. Move the mouse to the left side of the window until the mouse icon changes to a horizontal arrow that points in both directions.
2. Left-click and drag the mouse to the right until you see the folder view.