"unread mail" folder

[Harold]

I recently lost the folder called "unread mail". This folder was always in
the "favorite folder" pane in the upper left corner. I tried dragging
"unread mail", from "Search Folders", but it does not collect my unread mail
in one folder. I have many personal folders with corresponding rules to
deposit new mail in the folder I have designated. But, now I have to go from
each highlighted folder to read all of my new mail. How do I restore the
"unread mail" folder. The "unread mail" from "Search Folders" does not
collect my unread mail, in one folder.