The only available Yahoo Mail Notifier is a Firefox add-ons. Which is use to notify you about the latest incoming mails to your yahoo mail inbox. You will see a small icon in bottom right side of your firefox. Whenever a new mail will come, you will see a visualize message with a sound. You can see in the below screen shot.
Install Yahoo Mail Notifier
Download Yahoo Mail Notifier from Firefox Add-ons directory and install in your browser. Click on “Add to FireFox” button to install this add-ons. OR you can also click on the above link to go to the firefox add-ons page and install from there.
After the installation of the add-ons, restart your browser. Now you will see a box where you have to type your Email address and Password. You can also give a tick to the”Remember Password” so that you will not enter your login info again and again.
Now whenever new mails will come to your inbox. You will see a notification in the bottom ara of your browser. There is also another way through which you can get notifications for new mails. That is installing of Yahoo Tool Bar in your browser.
Visit here http://toolbar.yahoo.com/ to get tool bar for your browser.