When I follow your directions, as soon as the email comes in, it disappears. Having four email addresses, that doesn't seem to be that convenient, for although I'm notified by a sound when mail comes in, I have to look through each to see where it is.
Maybe I'm not following correctly. I went to Options / Mail / Reading Pane, checked off "Mark items as read" set the 5 to 0.
Whatever, this is still not working the way my main email address is. Any other suggestions?