Thunderbird is my first option e-mail client under Linux. Unfortunately, despite of years of urging, the application still lack the ability to close to tray, which is a deal breaker to me. 👎
There are some plugins of Thunderbird that enable close to tray option, but most of those them are either buggy, or discontinued. ☹
kdocker is an app similar to AllTray(Discontinued and no longer working). Although its name starts with letter ‘K’, the app claims to work on KDE, GNOME and XFCE.
No damn make install,
sudo apt install kdocker is enough.
kdocker thunderbird and the Thunderbird will start minimized.
Now every time you click minimize button, the app will minimize to the tray.
/usr/share/applications/thunderbird.desktop and change
Exec=thunderbird %u to
Exec=kdocker -mq thunderbird %u under [Desktop Entry]. The option -m will start the application in foreground and -q will disable notification for title change.
One problem is when you click the close button, the app will exit. According to the author of kdocker, overwriting close function is not going to be supported. Luckily for KDE users, the close button can be disabled easily, preventing misoperation to some extent.
Right click on the title bar and select More Actions > Configure Special Application Settings.
Under Appearance & Fixes Tab, check Closable, select Force, select No.
After saving the settings the Thunderbird can only quit within the app’s menu.