/usr/lib/x86_64-linux-gnu/libKF5Tnef.so is in libkf5tnef-dev 16.04.2-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libKF5Tnef.so.5
/usr/lib/x86_64-linux-gnu/libKF5Tnef.so.5