Hi, I just installed LinuxMint 18 KDE beta and setup Kontact and KMail. I noticed that when I save an e-mail I am writing (Ctrl-s) the editing window closes completely. Is this normal and if so, why?
I know the program can autosave drafts every .. minutes but when I do it by hand the window is closed.
Is there a setting somewhere I can change or is this "by design"?

This is still valid in current development code (I just tested this myself). It may be intended behavior, however you may want to file a bug on bugs.kde.org (file it against the kmail composer) showing the inconsistency between this and other programs (like Kate, where saving a file does not close the window).