Find what version of Thunderbird you are using Click the Application menu button , then go to the Help menu and choose Troubleshooting Information. A new tab will open with information about your setup. Under Application Basics, refer to the number beside Version. That is the version of Thunderbird you are using. Was this article helpful? These fine people helped write this article: Chris Ilias, Tonnes, Michele Rodaro. You can help too - find out how.