I think this is a useful feature, when clicked either minimize or close buttons could send Thunderbird to systray. One more thing is i dont know if it also exits: Start with windows & start minimized could be useful.
Having the option to minimize an app to the system tray when clicking the minimize or close button is really useful, especially for apps that need to stay running in the background just like Telegram does. It keeps the desktop clean while still allowing quick access when needed. If you want to see how smoothly this works in practice, click hereand try Telegram to experience this feature firsthand.
