Undelete Mail in Yahoo! To undelete a message in Yahoo! Mail: 1  Go to the Trash folder. 2  Open the desired message. 3  Click Move in the Yahoo! 4  Mail toolbar. 5  Select Inbox or any other folder to recover the message. 6  In Yahoo! 7  Mail, you can also drag and drop the email to any folder, of course.ail: 1  Go to the Trash folder. 2  Open the desired message. 3  Click Move in the Yahoo! 4  Select Inbox or any other folder to recover the message. 5  In Yahoo!