How do I switch back to Evolution and ensure that it is integrated with the desktop?

I would like to use Evolution as the default mail client. Thus, I'd like to have Evolution integrated with the desktop instead of Thunderbird (especially concerning the mail symbol on the desktop bar). Has anyone experience 'reverting' to Evolution?

I did change the Mail client setting in the Default Applications section in System Info dialog from 'Thunderbird' to 'Evolution'. This has the effect that the mail application started from Unity Launcher is indeed Evolution, yet, this setting does not replace Thunderbird with Evolution in the desktop bar. And, it does not enable desktop notifications for Evolution, as a consequence.

Install evolution-indicator, but DO NOT uninstall thunderbird, otherwise the indicator will not show.

sudo apt-get install evolution-indicator

Go to System settings, and click on System information and go the Predefined aplications and change Thunderbird to Evolution.