Yahoo! Mail Checker 1.0Free
Constantly checks your Yahoo email address and notifies you when you receive a new email. Automatically logs into your account and runs in the Windows tray.
Yahoo! Mail Checker brings you Yahoo! Mail to your desktop. It automatically logs in and checks new e-mails. You can choose an interval in minutes for checking new mails. And has options like start with windows and run in system tray are also available.