MS Access Query to update

Trying to update Packet.MSGState to P where if not R or D and it is Y in table Packet.MSGState

UPDATE Packet SET Packet.MSGState = 'P'
Where (MSGState <> 'R' and  MSGState <> 'D') and
Exists
(Select  MSGTO.Selected
From MSGTO
Where MSGTO.MSGTO = Packet.MSGTO and  MSGTO.Selected = 'Y')

Thanks Kevin