Follow these steps:
- Go to the Domains panel.
- For the relevant domain name, under the "E-Mail" column, choose "Manage."
- Select "Permanently Remove Forwarding" from the "Actions" box.
- Enter your password, select the confirmation checkbox, and select "Confirm Remove Email Forwarding."
NOTE: You will be charged for email forwarding until you remove it using the above steps; disabling it will not be sufficient.