Is there a convenient keyboard shortcut for scrolling an email message?
As it is I have to use the mouse to move focus to the message pane before I can scroll it. There are some shortcuts listed in the shortcut menu for changing focus, but they don't seem to work for me - and in any case, I don't want to change focus.

In Thunderbird, Space scroll the message forwards, and Shift-Space scrolls it backwards. That works pretty well. In Zimbra Space goes to the next message - but that is redundant, since the Down/Up arrow keys also work, and seem (to me) more natural.