In Apple Mail, is there a keyboard command to shift focus from a message to the message list

Solution 1:

On macOS Mojave, tab cycles between Mailbox list, message list, message and search bar.

Solution 2:

I've recently discovered that you can shift focus from a message to the message list with an awkward combination of two repetitions of ⇧⌥-Tab then ⌥-Tab. I.e. you can't "back up" to the message list; rather, you have to shift focus to it in the "forward" direction. It seems like there should be a better way to do this in a single keystroke. If anyone knows a better keystroke or shortcut, I'd love to hear it.

Solution 3:

You can enable Favorites bar where each element has shorcuts like ⌘1, going from 1 to 9. When you keystroke shortcut of an inbox its message list gets focus.

If you have multiple mail accunts you have to use corresponding shortcut for each inbox. This is not as ergonomic as a single shortcut would be though.