Mac OS - Outlook search return no result

Outlook for Mac uses Spotlight for searching. However, my Outlook refuse to search when I try my keyword in the search box.

Here is the official response from MS http://support.microsoft.com/kb/2473212

But the problem is, I don't have any mail category in System Preference -> Spotlight -> Search Result

So, my solution is as follow

1. Go to System Preference -> Spotlight -> Privacy
2. Click on + to add a Privacy

3. At the open dialog, select Macintosh HD and click choose

4. Click ok if the system ask for confirmation on selection Macintosh HD for privacy
5. You should see Macintosh HD appear on the Privacy box
6. Close Spotlight
7. Reopen Spotlight
8. Go to Privacy, select Macintosh HD and click on -
9. Now, Spotlight should be re-indexing the machine and Outlook should be searchable after the re-indexing.