When you sign in to Yahoo! Mail, you will see whether or not you have any unheard messages on the Welcome page. If you have new voice mail, you will see that you have unheard messages. Simply click on the unheard messages link, and Yahoo! Messenger will open and display your voice mail in a new window. Simply select any voice mail to hear your message. You can reply to the voice mail with an instant message or by making a voice call.