Minimize Outlook to the Notification Area instead to close

Some users wish to minimize Outlook to tray/notification area, instead to close, when click to x on the upper right corner. To do this, do the next:

Open Regedit and change/add next DWORD:

Key: HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Outlook\Preferences
Value name: MinToTray
Value type: REG_DWORD
Value: 1

After the change, save and restart the computer.

Also, one add-in can be installed: OLKeeper