Outlook 2011 for Mac users can configure their Yahoo Mail account using the options available as part of Account settings.
Step 1: Launch Outlook 2011 for Mac then the Preferences window.
Step 2: In the Outlook Preferences screen, click the Accounts option under Personal Settings.
Step 3: Now to Add a Yahoo Mail account, click Add an account option and select E-mai from the list.
Step 4: Enter the E-mail address and Password of your Yahoo Account in the Account Information box and click the Add Account button.
Step 5: This should automatically configure Yahoo Account in Outlook 2011.
If you have multiple accounts configured and want Yahoo Mail account as the default account then you can use the Set as Default option available in the Account Settings screen.