Thunderbird is managing four email addresses for me. I set them all up to have the most recent messages at the top of the list and I move through them from the bottom up. The first day, TB asked whether I wanted DELETE to move to the next higher email (which for me would be the next unread). Apparently I managed to click "Yes" for two of my email addresses but not for the other two. After a couple of times, this message never showed up again and I very much regret not having said "Yes" for the other two addresses. When I am reading them, a delete goes down to the message below, which for me, means a message I have already read. Then I have to click manually to move up to the next unread message. I have searched and searched for a way to tell TB I want to move UP after a deletion because that's where my next unread message is. It just keeps going DOWN to a message I have already read.