When opening Save and Open dialogs in Outlook (and other Office applications), there is a space on the left with some default locations.
How can I add my own locations?
The solution would depend a bit on your version of Outlook and Windows and, to make it even more confusing, the combination of the two matter as well.
Eventually you’ll either end up with a browser dialog from Windows or a browser dialog from Office.
Browser dialog from Office
The browser dialog from Office holds a My Places bar on the left side of the dialog. You’re likely to see this dialog when using Outlook 2003 or previous or when using Outlook on a Windows XP computer. To add your custom folder to it, browse to the folder in the right pane and select it (but do not open it). Then right click in the My Places area to see the Add option.
If the Add option is not available to you, you’ll see a Tools menu button in the right top of this dialog. When you expand that menu button you’ll find an “Add to My Places” option to reach the same results.
The context menu also allows you to sort your locations and change icon size
Browser dialog from Windows
When using Outlook 2007 or Outlook 2010 on Windows Vista or Windows 7, the browser dialog is provided by Windows instead of Office. When the dialog comes up, and you don’t see any locations on the left side, press the “Browse Folders” expansion button at the left bottom. To add your own custom folder to the Favorites list on the left, browse to the folder in the right pane and drag and drop it into the Favorites list.
Make sure you drop it exactly between the icons to add the folder as a link.