I updated to Oneiric recently and now the messaging menu is not working properly for Thunderbird anymore. When I get a new e-mail, the envelope does not change at all (No visible notification). Additionally no bubble appears telling me about the new message. How can I change this behavior?
You may need to disable any extension you had working in 11.04 to get this functionality. According to the details of the one I had, it is now integrated into the Ubuntu Oneiric version of Thunderbird, and they recommend disabling the original add-on. After doing so, my indicator pop-up is working. (However, I still don't get an unread message counter on the Thunderbird icon in the Unity launcher...)