Subfolders, or folders, are a way for you to organize messages that you have received. Folders are always listed to the left of your messages. You may create subfolders within folders if you wish. To move messages to one of your folders simply select the checkboxes beside the messages you want to move, select the folder from the drop down menu at the bottom and click move.

If you delete a folder, all subfolders within that folder will be permanently deleted. And all messages residing in that folder and the subfolders will be moved to your trash.