To restore native scrollbars:
Mac OS X (Thanks to Arronax): Extract nativescrollbars.css from Thunderbird.app > Contents > MacOS > chrome > classic.jar > global. Copy nativescrollbars.css into tigermail-2.1.1-tb.jar > global.
Windows: Extract xulscrollbars.css from Program Files > Mozilla Thunderbird > chrome > classic.jar > skin > classic > global. Replace xulscrollbars.css from tigermail-2.1.1-tb.jar > global.
Use any zip program to view .jar files.
** If there is any version update to the Tiger Mail theme, you will need to repeat the steps above **
Multiple email accounts (Thanks to Sam):
Use this extension to get all new messages: Easy Get Mail (https://addons.mozilla.org/thunderbird/1877/)
Known issues: Calendar and Lightning extension not fully compatible
What's new in version 2.1.1:
* Native fonts used
* Selected sort header is highlighted
* Folders show bold font for new messages and normal font if not
* More display glitches fixed
Tips:
* To align button spacing on the toolbar:
Right click on the toolbar, select "Customize", then drag and drop multiple "Space" icons (or "Flexible Space" if preferred) to the toolbar.
* To remove the menu underlined letters:
Click Tools > Options > Advanced > General > Config Editor.
Enter "ui.key.menuAccessKey" in the filter, and change the value to "0".
* Re-arrange the toolbar icons as per the preview screenshot or to your liking.