I kept wondering for several months to find a solution to read my yahoo email in outlook. But every source claimed that we need Yahoo Mail Plus subscription for this. But finally I found a solution to do this without subscribing for Yahoo Mail Plus.
YPOPs 0.9.5 for windows does this all for you, and does this for free. YPOPs! is a free open source software that provides POP3 and SMTP access to Yahoo! Mail. You can use your favorite email client, be it Outlook, Thunderbird, or whatever else you like and connect to Yahoo! Mail seamlessly.