I'm sure I read somewhere that you could do this but I've no idea how! I know you can with Hotmail but is the same true for Yahoo? What I'd like is to be able to open Outlook and and have a folder for Yahoo which would notify me if I had any emails?
A few years ago, Yahoo offered free Pop3 access on my yahoo .co.uk account, which I still use, for free.
Recently, I created another account on yahoo .com, and thought I could use the same POP3 access (with suitable changes to the server addresses), but it didn't work (unless I pay).
I don't know whether it's because Yahoo has stopped the free POP3 access for new accounts, or it's because of the domain difference as pointed out by beeuuem.
Anyway, I now use a program called YahooPops (or sometimes called YPops) to access my yahoo .com mail through OE and Outlook. It's the same program that beeuuem referred to earlier. You can click here to download the program. The server on that site is quite often very slow. If you can't access it, try again later or another day. It works.