Recently upgraded to Ubuntu 11.04.
There are lot of discussions on the move to Unity Desktop by Ubuntu. Though it looks easy than Gnome, for me, personally, it is not nice to move to unity now. There are a lot of things to fix. Some components are giving issues and the community is fixing them faster and providing awesome support via mailing lists, forum and irc.
At this point, instead of playing with Unity, decided to explore KDE.
When adding my email account, Kmail shows the following error.
Here is the solution to fix the akonadi error.
sudo aa-complain mysqld
sudo /etc/init.d/apparmor reload
sudo aa-complain mysqld-akonadi
sudo /etc/init.d/apparmor reload akonadictl start
Now, kmail works fine.