/usr/lib/libmessageviewer.so.4 is in libmessageviewer4 4:4.8.2-0ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libmessageviewer.so.4.8.0
/usr/lib/libmessageviewer.so.4.8.0