Is there a way to show unread count on Messaging Menu icon, without opening it? I'm using Ubuntu 11.04.
As far as I know this isn't available yet and wouldn't be able to be done without some serious hackery.
May I ask why you would want this? It already indicates that there are new things and you have to click on it to see what needs attention. Having a badge wouldn't really help as it gives no more context than a highlighted mail icon. Also, what happens if you have an unread account with, say, 100+ unread messages? It would be hard to read and not very helpful.
I believe there are mail checker panel applets that have badge functionality, but it's not an aggregate view like the Messaging Menu.