I sort many of my messages into folders and subfolders by using rules. While I do use a Search Folder to keep track of all the new messages, the new messages still expand the folder list which is fairly large.

The result is that the Navigation Pane looks quite cluttered and it pushes my other mailboxes down and out of view and I need to scroll down to see them.

Is there a way to prevent these subfolders from being opened or to quickly collapse them all at once?