/usr/lib/x86_64-linux-gnu/libmapi.so is in libmapi-dev 1:2.0-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmapi.so.2.0
/usr/lib/x86_64-linux-gnu/libmapi.so.2.0