If you are using NS other than the Default ones here (Enom) - You can't use the Email forwarding provided here.
If you are hosting the domain you can set it up at your host more or less the same way though.
If it is parked - I'm not sure what would be the easiest route or if there is any way to do it at all.
You could use domain forwarding to point it at the the parked page (Providing the parking service allows this) - But that generally could hurt the domain on SEO depending on how you forward it.