Search Folders are a quick and convenient way to look at predefined collections of email messages. They don't actually store any messages themselves but, instead, are virtual folders that offer a view of all the messages stored in your mailbox depending on the attributes you've defined. Outlook provides default Search Folders—such as Unread Mail—but you can also create your own. For instance, you can use Search Folders to help you find all the information related to a particular project, an important client, or an upcoming conference.
To create a Search Folder in Outlook 2010, in Mail, on the Folder tab, in the New group, click New Search Folder.
To create a Search Folder in Outlook 2007 or Outlook 2003, in Mail, on the File menu, point to New, and then click Search Folder.
In all versions of Outlook, specify whether you want to use a predefined Search Folder or to create your own custom folder, and then follow the instructions on the screen.