When you are finished, click the red close button in the upper-left corner to close the window. Click Force Quit to quit the application. Select the application in the Force Quit Application window, and then select Force Quit. If you cannot quit an application or do not know how, hold down the Command and Option keys, and then press Esc on your keyboard. To quit an application, click the menu on the toolbar (top), and then select Quit.
You must quit all applications before you continue with the following steps. That is a multiple step procedure and lengthy process so be ready for some work.
Usually the maker (Microsoft) recommends the first thing to do is to REBUILD the database Rebuild the Outlook for Mac 2011 database to resolve problems as recomended by Microsoft
