One of my personal pet peeves during the first week of using Thunderbird was the lack of system tray nofitication about the new mail. Apparently this functionality is only available on Windows. And I really missed the KMail system tray functionality with the number of unread messages shown right on the system tray icon. And there seem to be no plugin extension which would provide this functionality…
However after looking carefully I found the FireTray extension. The current official version does not work with Thunderbird, but the development version does. To install it you need to:
- Open the FireTray extension web page and scroll down to the bottom until you see the “Development Channel” section.
- Click on it and you will see the yellow extension button. Right-click on it, select “Save as…” and store it somewhere.
- Switch to Thunderbird, open the Add-ons Manager, go to “Extension” tab, and look above it on the search edit field. On the left side of this field you’ll see the wrench icon with the arrow down. Click on it, and in the opened menu select “Install Add-On from a file…”
- Go through the usual warnings, install the add-on and restart Thunderbird.
- Open Add-ons manager and go to the Preferences of FireTray plugin.
- Enable the “Closing window hides it to tray” checkbox in the General tab. Switch to “Mail” tab.
- Select the “display unread message count” radio button and press the “Text color” button. Select the dark blue color.
- Close the dialog
You now have the system tray icon with the unread email count. Now, what if you want to change the icon? Simple.
Go to your Thunderbird profile directory (typically /your/home/.thunderbird/<randomstring>.default/extensions/.
Find there the directory {9533f794-00b4-4354-aa15-c2bbda6989f8}/chrome/skin and enter it. It contains several PNG files. Get your 32×32 icon in PNG format and replace the existing blank-icon.png and thunderbird32.png files with your icon.
Restart Thunderbird, and now you have the new icons.