BookMarkAutoHider Thunderbird Extension
This extension hides the BookMark toolbar until you move the mouse into/above the Menu bar.*1
To install the BookMarkAutoHider Firefox extension:
Click the following link:
Click any security query to allow installation.
When the grey "Install ..." button on the Software Installation dialog
changes to black "Install Now", click it.
The code for this extension is from
Bookmark Autohider, by
with the minor addition of sensing the cursor in more fields (the unified search bar, main menu, and
I made these changes because I combine all those fields into a single customized tool bar.