Thunderbird-DontRestoreTabs 1.2 Requires Restart
by Paolo "Kaosmos"
Allows the user not to restore tabs at startup in Thundertbird
About this Add-on
In the "View" menu it will appear a new option to restore tabs at startup, by default it's not checked.
If you want to hide this menu item, you can set the preference "extensions.dontrestoretabs.nomenu" to false (restart required).