new maildir folders
creates new maildir folders.
Parent directories are created as needed, and attempting to create an existing
maildir is not an error.
New maildir folders are created with mode 0700, i.e. readable and writable by
the owner only.
utility exits 0 on success,
and >0 if an error occurs.
does not support maildir++, you need to
transform nested maildir++ folder names yourself.
is in the public domain.
To the extent possible under law, the creator of this work has waived all
copyright and related or neighboring rights to this work.