mailman 1:2.1.26-1 / usr / lib / mailman / bin / postfix-to-mailman.py

/usr/lib/mailman/bin/postfix-to-mailman.py is in mailman 1:2.1.26-1.

This file is owned by root:root, with mode 0o777.

It is a symlink to /etc/mailman/postfix-to-mailman.py