Seth is totally right.
When subscribing to some RSS feeds via Outlook, a subfolder is NOT
automatically created, for some it is.
When the subfolder is not automatically created the unread mail are
shown in parenthesis for the root folder, however the items canot be
accessed. I could access them via the Unread Mail search folder. The
root folder only displays a sort of welcome message from Microsoft.

Pietje Puk.