The steps vary a bit from device to device, but the following steps work on older Nokia S60 devices (as Nokia E71, X6-00, 5230 and similar) in which has not have the built-in Nokia Mail Client:
- On the device, select the menu key.
- Select Installations.
- Select Email.
- Highlight the mailbox that needs to be removed.
- Select Options.
- Select Remove mailbox.
- Select Yes.
Reboot device by removing battery after mailbox has been removed.