I have adjusted the view message option to make a better use of the folders. The main goal was to avoid opening up new windows as this is a problem for some users. While doing it, I took the occasion to enhance some of its functionalities.

At the bottom of a message, in a secondary toolbar, which also solves some issues about message alignment when there is a lot of options, there is the ability to manage/view the folders as well as a one click access to saving the message into one of them.

Let me know what you think. If this is better, I'll adjust the map and list folder options to use a similar route as well.