Once you have enabled AutoComplete, you may begin by logging into your Yahoo!Xtra Mail account at Yahoo!Xtra Mail.
Click the "Compose" button to start writing a new email.
You may type the first name, last name, nickname, or email address of a contact in your Yahoo!Xtra Address Book in the "To:," "Cc:," or "Bcc:" field. Select a recipient from the dropdown menu that contains suggestions provided by Yahoo!Xtra Address AutoComplete. You can also use the keyboard arrow keys to select an address and use the Enter key to insert it. To add more addresses repeat the above steps.
Please Note: Yahoo!Xtra Address AutoComplete can only recognize those contacts already entered in your Yahoo!Xtra Address Book. Yahoo! has several tools available for adding contacts to your Yahoo!Xtra Address Book.