How to set up Yahoo account on Windows Phone
To set up an email account on your phone, you must have a working cellular data or Wi-Fi connection. If your contacts are stored on your PC, you’ll need to import them into Yahoo account or another online service before you can sync them to your phone.
1. On Start, flick left to the App list, tap Settings , and then tap Email + accounts.
2. Tap Add an account >> Yahoo! Mail.
3. Tap the Email address box, and then type your Yahoo! ID.
4. Tap the Password box, and then type your password.
5. Tap Sign in.
Your Yahoo! Mail email will be synced to your phone.