When email messages are deleted they usually go to the Trash Bin, or Recycle Bin, and can be restored easily to their original location. Email messages deleted from the Trash are considered permanently deleted by all email programs. There are neither general nor easy ways to retrieve email deleted permanently. The usual strategy is to rely on a backup of the mailbox. Some Web-based mail services allow you to successfully retrieve deleted mailbox content because, for limited time, they keep backups. Yahoo Mail can do a rollback of a mailbox to the time specified by the user.
Launch a Web browser and navigate to Yahoo Mail (see Resources).
Log in to the Yahoo account by providing your Yahoo ID and password.
Decide on the account rollback time. It should be about one hour before you deleted the message from the Trash. For example, if a message was deleted from the Trash at 5:15 p.m., choose the mailbox reset time for 4:15 p.m.
Save, print or forward to another account all messages received after the time selected in Step 3. Anything you receive after that time will be removed when the mailbox is restored.
Click on another browser tab and navigate to the Yahoo Mail/Messenger Restore Help Form (see Resources).
Enter your name and make sure the correct entries are in the drop-down menus. Yahoo will fill in your email address and alternate email address from their database.
Select a problem description from the drop-down menu.
Select the month, date and time (15-minute increments) that you determined earlier for the restore time.
Click "Submit" on the bottom of the page.
Continue monitoring the mailbox and keep backing up all incoming messages until the restore process is complete.
Yahoo will send a confirmation email to the alternate account when the process is complete, usually six to eight hours.
Your mailbox can only be restored for 48 hours, so act quickly.
All folders in the mailbox are restored by the recovery procedure, not just the Trash. Avoid choosing an exact time when an email was deleted since the mailbox could be restored at the point when the email is still deleted.