Is there a keyboard shortcut in Gmail which fully returns focus to the message list? The help short cut (?) shows a comma , as "Move focus to toolbar", but when I move it there, I can't get it back without clicking with the mouse.
Similarly, I sometimes get focus placed on the menu of other Google services at the top of the page.
In each of these situations, the indicator of the current message moves around with j or k, but if I hit enter, it does not open the message.