As of Notes 9.0.1, you can now control the date column in the mailfile preferences to automatically sort ascending or descending. (
The option can also be set via the notes.ini
AUTO_SORT_DATE=11 or 12
A value of 11 displays the most recent message at the end of the view (the default) and 12 displays it at the beginning of the view.
Work also in Notes 9.0.0 (my current client/server Version)