I am using Thunderbird (version 68.7) on a fresh install of Ubuntu 20.04 but I do not get any notification popup in the system tray.
I switched on notifications in the Thunderbird settings and notifications from other applications (such as Ubuntu Software Updater) are visible.
Besides, I used the same Thunderbird configuration on Ubuntu 19.04 earlier (as kept the config files and stored messages on my home partition)
Do I need to install any additional packages?
