Kwaga BirdsEye is a great appplication that works with Yahoo! and Gmail email addresses. Alerts you on your desktop when you receive emails that require your attention - only the ones that matter!
Use any Yahoo!, Gmail or Google Apps email address or even multiple Gmail email addresses, for example. Simply download, configure it, and keep it running.
Mia for Gmail (was Notifier Pro for Gmail) is a desktop Gmail client which sits politely in your menu bar.
