Main Window Layout in Thunderbird

Thunderbird comes with three variations on the layout of the main window.

To select a different layout, from Thunderbird's View menu select Layout, then select Classic View, Wide View, or Vertical View. In the View - Layout menu you can also check or uncheck (to display or hide) the Message Pane. By default, the Message Pane is checked (and therefore visible).

You can resize the sections of any layout by dragging the borders of the area (your cursor will change to a double-headed arrow).

The default layout is Classic View. The folder area is on the left, the message list is on the right, and the message pane is at the bottom right.

Wide view is like Classic View, except that the message pane extends all the way across the bottom, which allows more text to be visible.

Vertical view puts the three sections into columns: folder area, message list, and message pane.