Minimize Outlook 2002 to the Tray

*** Outlook 2003 has the capability to minimize to tray built in ***
If you want to "tray" Outlook you need to create this registry key and set the value of MinToTray to 1.
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Preferences]"MinToTray"=dword:00000001
To start the registry editor, from the Start menu, Run dialog, enter regedit. That will open the registry editor. Browse down the tree until you get to Preferences under Outlook. On the right side of the screen, right click as choose New DWORD, as shown in the screenshot. Name it MinToTray and change the value to 1 (right click on it after naming it and choose Modify)
Close outlook and reopen it for the change to take effect. Now when you minimize it, there will be an icon in the tray area. Double click on it to restore. To remove the feature, delete or rename the key.