The way the highlight always moves down when the Delete
key is counter productive when the list is sorted in
reverse order by date, as in newest on top so that the
list doesn't need scrolled to see the latest messages.
I think the highlight would be best left in place like
it used to be and like it is now when clicking the
Delete toolbar button, or maybe better yet, allow the
user to configure whether the highlight moves and which
direction if it does.