[Exim] Maildir directory spec problem

Yes I RTFM. Really

If ~/Maildir is specified.. new email is put into ~/Maildir. As I
understand it, new mail should go into ~/Maildir/tmp and them be moved
into ~/Maildir/new - automatically when ~/Maildir is specified...

This is not happening. if ~/Maildir is specified, new mail ends up in
~/Maildir

exim v3.22

Thank you.