Yahoo! Mail Notifier 0.9.9.6 - Notification of new messages by Firefox browser

Normally, if you use Yahoo! Xtra Chat. Messenger when Yahoo! New, you will be notified it soon. But if you are not chatting and do not use the program but want to know if you have new or not, this can be done with the Firefox browser.
For Firefox to get this feature, run it and go to http://downloads.mozdev.org/ymnotifier/ym_notifier_0.9.9.6.xpi, download an extension called Yahoo Mail Notifier (new version). After installing and reopening Firefox, you will see an envelope icon in the lower right corner of the browser window.

Next, you need to provide the mailbox account you want to use in the Yahoo Login, including your Yahoo! username and password. To keep your account secure without having to re-enter it each time you visit Firefox, check the Remember password box. Finally, click Login.
Each time a new message arrives, you'll see the envelope icon light up, and you'll see the number of new messages appear next to it. To log in and view messages, just double-click the envelope icon.
You will be notified of new mail every 5 minutes. To change this time, right-click the envelope icon, choose Preferences, enter the number of minutes in the Check for mail every box, and then click OK. If you want to check for new mail or change account information, from the context menu, select Check Now or choose Change Username / Password.