Here are the steps on how to find the email address of all your Facebook contacts through Yahoo! Mail. 1. Once you are logged in to your Yahoo! mail account, go to "Contacts" tab and then click on the "Import Contacts" button.
2. Click the Facebook icon to begin importing your friend's contact details.
3. Importation may take a while especially if you have several connections. You will be notified when the action is finished. Click "Done" and you will now see the imported email addresses on your Yahoo! contact list.
4. If you want to export your contact list to a CSV file, note that the option is there but will not work for your Facebook contacts. The work around is to view your contact list in "Print" form and then copy-paste them to excel or notepad.