A search folder find items that meet a specific set of conditions that you define and displace those items any time you click on the folder.
Keep in mind that your messages aren't stored in these folders, but you can work with those messages like you would any other; for example, you can delete, edit, reply to, or move them.
If a search folder is in italics it means it hasn't been updated recently. Once you click the folder, Outlook will update the search and remove the italics from the folder's name.
Here are some examples of search folders and how you can use them every day:
Creating a search folder is easy. Click Folder > New Search Folder.
Figure 1: The New Search Folder button is being selected.
This window will appear:
Figure 2: The New Search folder window.
Click a mail type at the top and then set your criteria as instructed at the bottom and click OK.
Figure 3: The New Search Folder window.
The new folder will appear in the Search Folders list.
Figure 4: The search folders list.