Looks like the problem is that evolution-indicator doesn't depend on evolution:
$ apt-cache rdepends evolution-indicator evolution-indicator Reverse Depends: ubuntu-sugar-remix ubuntu-chinese-desktop ubuntu-desktop
If you remove the evolution-indicator package, the "Set up mail" item goes away.
Looks like the problem is that evolution-indicator doesn't depend on evolution:
$ apt-cache rdepends evolution-indicator sugar-remix chinese- desktop
evolution-indicator
Reverse Depends:
ubuntu-
ubuntu-
ubuntu-desktop
If you remove the evolution-indicator package, the "Set up mail" item goes away.