Few days ago, Evolution, the fully featured e-mail client for Gnome desktop has updated to their latest version - 3. As I said before, this is a fully featured mail client which comes with a powerful GUI interface for managing/mapping ports, calender, address book, etc.
Although this new version does not bring any new features... other than few bug fixes but as said before, this will integrate better with your existing Gnome 3 nonetheless.
So, if you don't use this much often, then I don't think that you have to update this.. but still if you use it from time to time or a faithful regular user, then it's better to do so :). If you use Gnome 3 in Ubuntu 11.04 Natty Narwhal, then you can install Evolution 3 by using a PPA channel.
To do that, simply open your Terminal and issue the below command.
sudo apt-add-repository ppa:danilo/evolution
sudo apt-get update
sudo apt-get install evolution