I really like the double clicking to open in a new window though there is a tiny problem with it.
Double clicking the message in the message list is fine, but it also opens in a new window if the actuall message in the bottom pane is double clicked. This causes a problem because to highlight a single word easily it also requires a double click. It would be nice if double clicking to new window was limited to the message list pane.
Consider it done.
Cheers,
Wilson.