This is the comment thread for the release announcement of K-9 Mail 6.000.
Just arrived this morning on my phone. Everything appears normal. 
For me as well: 6.000 and all works well. 
Strange: I left Beta and Google Play tells me that Beta version is still installed. Maybe this will vanish if 6.001 will come out…
It is now possible to show the number of starred messages.
Is it also possible to go to the list of starred messages when tapping the number? Same for the number of unread messages.