Windows 8’s Mail app has a fresh, modern look and works great if you’re signed in with a Microsoft account — your Hotmail or Outlook mail shows up automatically. But it also supports Gmail and Yahoo accounts, which is handy. Here’s how to set them up.
Step 1: Sign in to the Windows 8 Mail app with your Microsoft account. If you don’t have one, sign up — you don’t need a new email address, you can use your existing one.
Step 2: Once signed in, open the mail settings. The quickest way is Win + I to open the settings charm, then select Accounts.
Step 3: Tap Add an account, choose Gmail or Yahoo from the list, enter your credentials, and you’re all set.

That’s it. You can now send and receive mail from your Gmail or Yahoo account right inside the Windows 8 Mail app.
Hello Ankur,
This was quite easy and I suppose most of the people knew it but can you please tell how to add your gmail account in the Windows 8 messaging?
The Windows 8 messaging currently supports only Microsoft and Facebook accounts.
Windows 8 Messaging app can access exactly two messenger-type services: Microsoft Messenger and Facebook Chat and you can only configure one account of each type.
http://winsupersite.com/article/windows8/windows-8-review-part-4-productivity-apps-144539
Ok Ankur this is good, but if yahoo is not on the list, you need to follow this video thats help:
this is good. but the problem is, i don’t have yahoo on my list..any suggestion
Check this video suggested @MKF
why do yahoo and aol not appear on my pc? are my settings wrong?