Welcome to Thunderbird Add-ons.
Add extra features and styles to make Thunderbird your own.Close
Text size toolbar 0.6.2 Requires Restart
Adds text size buttons to the toolbar. This has now been superseded by the Zoom toolbar https://addons.mozilla.org/en-US/firefox/addon/6118
About this Add-on
After installing use View > Toolbars > Customize... to add the buttons to the toolbar.