/usr/share/doc/exim4-daemon-light/changelog.gz is in exim4-daemon-light 4.90.1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/exim4-daemon-light/../exim4-base/changelog.gz
/usr/share/doc/exim4-daemon-light/../exim4-base/changelog.gz