/usr/lib/ is in postfix-cluebringer 2.0.10-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/postfix-cluebringer/cbp/protocols/
/usr/lib/postfix-cluebringer/
/usr/lib/postfix-cluebringer/cbp/
/usr/lib/postfix-cluebringer/cbp/protocols/Bizanga.pm
/usr/lib/postfix-cluebringer/cbp/protocols/Postfix.pm
/usr/lib/postfix-cluebringer/cbp/logging.pm
/usr/lib/postfix-cluebringer/cbp/system.pm
/usr/lib/postfix-cluebringer/cbp/policies.pm
/usr/lib/postfix-cluebringer/cbp/dblayer.pm
/usr/lib/postfix-cluebringer/cbp/dbilayer.pm
/usr/lib/postfix-cluebringer/cbp/cache.pm
/usr/lib/postfix-cluebringer/cbp/modules/
/usr/lib/postfix-cluebringer/cbp/modules/Quotas.pm
/usr/lib/postfix-cluebringer/cbp/modules/README.txt
/usr/lib/postfix-cluebringer/cbp/modules/Core.pm
/usr/lib/postfix-cluebringer/cbp/modules/CheckHelo.pm
/usr/lib/postfix-cluebringer/cbp/modules/AccessControl.pm
/usr/lib/postfix-cluebringer/cbp/modules/CheckSPF.pm
/usr/lib/postfix-cluebringer/cbp/modules/Greylisting.pm
/usr/lib/postfix-cluebringer/cbp/tracking.pm
/usr/lib/postfix-cluebringer/cbp/config.pm
/usr/lib/postfix-cluebringer/cbp/protocols.pm
/usr/lib/postfix-cluebringer/cbp/version.pm