Have 824 w/ DR5 and 4 port Nam. Trying to figure best way to have call that comes into auto attendant, transfer to a outside phone number when caller dials a mailbox. Set up a MB 300, caller dials 7 to go to a destination phone number. Tried to set up different ways and cant get it to work. Awhile ago, it was working through MB 229.I get a prompt that says " Line or line pool configured for this call is not valid." Outdial was changed to Pool