To import your address book from Facebook, Gmail, Outlook.com or a different Yahoo Mail account into Yahoo Mail: Click Contacts at the top left of the Yahoo Mail screen. Select Import Contacts in the main mail screen.

Yahoo mail provides easy to use tools to enable you to import email contacts into Yahoo Mail, and also to export Yahoo mail contacts from your Yahoo account.. You can use these import/export tools to move email contacts from one email system (e.g. Yahoo)

To import contacts from MS Outlook account to Yahoo Mail, you can perform the first three steps like the above procedure. Then follow these steps: Choose the Outlook option from the appeared list and click on the Import button .