How do you remotely change the greeting on the main mailbox with this system? When I call the main number, dial **, then enter the mailbox # and passcode, the prompt tells me the mailbox # and passcode are not registered.

To remotely administer you must have a password assigned to the admin mb other than default.

The password has been changed. I call the main number - enter ** then the mailbox number and password then press #. Each time, the prompt tells me that the mailbox # and password have not been registered.