Yes! You can read your Yahoo! Mail messages in Netscape, Eudora, Thunderbird, Outlook or other desktop clients by subscribing to the Yahoo! Mail Plus service.
With Yahoo! Mail Plus, you can also:
Subscribe and set up your Yahoo! Mail Plus account to read your messages in another email program. Click Options, choose "POP Access & Forwarding," and follow the directions.
You can always visit and make use of the Yahoo! Mail web site whenever you like, even if you're accessing your Yahoo! Mail through a different interface.