When you delete a mailbox, you delete the email address and all of its email messages. To delete a mailbox, log into the control panel, and perform the following steps:
1. In the Email Accounts section, click on the Add / Edit Mailbox link.
2. Check the box next to each mailbox that you'd like to remove. If you wish to delete all of the available mailboxes, click the checkbox that appears next to the Select Action drop-down menu.
3. Click the Select Action drop-down menu and select Delete Mailboxes.
4. When prompted to confirm that you want to delete the mailbox(es), click the "Delete mailbox(es)” button.