Fix Thunderbird Tabs Position

Thunderbird 11 changes the tab position from being below the menu bar to above it. If this is annoying to you and you would like the tabs back below the menu bar, download this add-on for Thunderbird and install it.To do so

• Go to this page, right-click on  the Download Now button and save the file to your computer.
• Open Thunderbird (if you haven't update to version 11 yet, do so by clicking on Help, About Thunderbird, Check for Updates...), Tools, Add Ons.
• Click on the button with the cog wheel on it beside the Search for all add-ons field
• Select Install Add-on From File
• Navigate to where you saved the file, select it and choose Open
• Now your tabs should be back below the Menu bar