A quote from their blog site: From Yahoo!'s point of view, any type of signed-in user engaging with Yahoo! services is a valued individual, whether she validates making use of a Yahoo!, Facebook, or Google ID.
How To Open Yahoo Mail Using Facebook
Login to Yahoo Mail account on PC/Desktop computer
First you require a username and password; now open internet browser from your computer/desktop. Then open web page www.yahoomail.com on it. To launch their new "one-click" sign-in merely click on the "Sign in with: Facebook" symbol on the Yahoo! login display. That's all you require; to obtain gain access to of your Yahoo mail account.
Login to Yahoo Mail account on Mac computer
If you are an individual of Mac computer after that Safari must be your web internet browser. Safari is the best browsing remedy for Mac OS; Safari fasts, faster and also easy to use web browser. You could quickly access your Yahoo Mail account with it. See, how to login with Yahoo mail account on Safari browser. Merely open Safari as well as kind www.yahoomail.com; you will be routed to Yahoo mail sign-in page. To start their new "one-click" sign-in simply click the "Sign in with: Facebook". You are after that completely signed into Yahoo!
Nevertheless, a recommendation- you still will not be able to sign right into a mobile or desktop computer customer making use of Google OpenID.
I wish this post can help you. Thank you ...