keyboard command to scroll viewer window?
I'm running the current version of mail.app (9.3) in OS X 10.11.5 (El Capitan).
I would like to be able to do basic operation of reading email with keyboard commands. There are keyboard shortcuts to create new messages, reply to or delete messages, move up/down through the list of messages in the message list pane, etc. That is great. But for the most common task of simply reading messages, support for keyboard commands is lacking.
In previous versions of Mail.app, i could use arrow keys to move around in the messages list window and I could use page-up and page down commands (fn-uparrow and fn-downarrow on macbook pro keyboard) to scroll the message view pane up and down. It was also possible to scroll up/down in the message window by using space and shift space. Both page-up/page-down and spacebar/shift-spacebar are consistent with general Mac conventions, including Safari.
In El Capitan, it seems this functionality was removed. Instead page-up and page-down just cause the message list window to scroll. Space does nothing. A workaround of sorts is to hit hit tab to shift the keyboard focus from the message list to the message viewer, followed by scroll commands, then either hit tab two more times or hit shift-tab (but not space or shift-space) to switch focus back to the message list again. This is not convenient for an operation that i do easily hundreds of times each day.
Anyone have any ideas on whether it is possible to restore the old functionality? Hacks like hidden mail preferences settings? ... or some way to use a resource editor utility (does that kind of thing even exist any more?) to modify the application?
Was this an old feature that just got forgotten/abandoned by Apple? Or was it a bug or oversight that this was omitted from the new version? Did Apple deem it as inconsistent with new interface guidelines? Was this functionality replaced some other keyboard shortcut that I just don't know about? Is there a 3rd party plugin or something I can use? Any insights would be appreciated.
MacBook Pro, OS X El Capitan (10.11.5)