To turn your catch-all mailbox on or off:
Click "Additional Options".
Email Control Panel: Additional Options Link
In the blue "Catch-all Mailbox" section, click "Assign catch-all".
Email Control Panel: Assign catch-all Link
In the pop-up Assign catch-all dialog box, choose an email address to use as the catch-all and click the Save button.(Note that only active users will appear in the pop-up.)
Email Control Panel: Assign catch-all Dialog Box
If you decide you don't want a catch-all, click "I don't want a catch-all mailbox" and click the Save button.
Email Control Panel: Assign catch-all Dialog Box
You will be returned to the Email Control Panel showing a message indicating the email address to which the catch-all is assigned.
Email Control Panel: Catch-all Assigned Message
Note: If you have a Custom Mailbox account which includes one email address, you may use a catch-all mailbox, but you use the default email address as the catch-all. If you have a Business Mail, Web Hosting, or Merchant Solutions account, you may designate any active email user's email address as the catch-all.