Add option to keep Thunderbird running in system tray when closing the main window

[kai_yang]

Many users (especially in regions like East Asia) prefer the behavior that when clicking the close button (X), Thunderbird does not fully quit but stays in the system tray.

This behavior is very common in other mail clients like Foxmail, QQ Mail, and is convenient for receiving new mail notifications while keeping the desktop clean.

Please consider adding an option like “Keep Thunderbird in system tray when closing the main window”.

Thanks for the great work and for considering this suggestion!

[Jon]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.

[siffemcon]

There is an add-on which does that, but it only works on ESR versions - the latest is 140.

[flaqueman]

...and it doesn't work on cinnamon desktop.

Please make it universal