People often ask me how they can search Outlook for folder names because they created so many folders, often nested so deeply, that they can't easily find folders when they need them. Unfortunately, Outlook doesn't support a way to search for folders, so it's important to use a good filing method, such as the one Keith Collyer uses:
I gave up on complex folder structures and simply have a set of A-Z folders, with the folders containing messages under these. Now I don't have to worry about whether I put something under "Customers" or "Projects", I just need to remember the name of the customer. Unless I get a huge number of messages for a customer on very different topics, I just put all the stuff in one folder. So "Big Company" goes under "B / Big Company", unless I get a very different topic to work on for them, when I add "B / Big Company - Topic", at the same level as the original "B / Big Company" rather than nested. It sounds too simple to work, but it is much easier to use and find stuff than any structure I had before. Of course, my Windows file system has the same structure.
Folder: Find a folder by its name (VBOffice.net)