Yahoo! Business Mail offers a convenient way to add people to your contacts from the emails they send to you.
To add the sender of an email to Contacts:
Click the plus (+) symbol.
Email Add to Contacts Plus (+) Button
An Add to Contacts dialog box opens with some of the information completed for you. Fill in additional information as desired and click the Save button
Email Add to Contacts Dialog Box
A confirmation message appears confirming that the contact has been added. Click the Done button to return to the email message you were reading.
Email Contact Added Confirmation