Hallo Steffen, thank you very much for the detailed explanation of your security considerations. The concept looks sound for me. And I keep /usr/lib/s-nail/s-nail-privsep SETUID root.
And for your next e-mail: My fault. I searched the man-page for "dotlock" but overlooked the "a"-example. The manual is really elaborated which I value much. Regards, Jörg-Volker.
