/usr/ is in ruby-actionmailer-3.2 3.2.16-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/action_mailer/
/usr/lib/ruby/vendor_ruby/action_mailer/collector.rb
/usr/share/rubygems-integration/
/usr/lib/ruby/vendor_ruby/action_mailer/test_helper.rb
/usr/lib/ruby/vendor_ruby/action_mailer/delivery_methods.rb
/usr/lib/ruby/vendor_ruby/action_mailer/railtie.rb
/usr/lib/ruby/vendor_ruby/action_mailer/log_subscriber.rb
/usr/lib/ruby/vendor_ruby/action_mailer/version.rb
/usr/lib/ruby/vendor_ruby/action_mailer/base.rb
/usr/lib/ruby/vendor_ruby/action_mailer/mail_helper.rb
/usr/lib/ruby/vendor_ruby/action_mailer/test_case.rb
/usr/lib/ruby/vendor_ruby/rails/
/usr/lib/ruby/vendor_ruby/rails/generators/
/usr/lib/ruby/vendor_ruby/rails/generators/mailer/
/usr/lib/ruby/vendor_ruby/rails/generators/mailer/USAGE
/usr/lib/ruby/vendor_ruby/rails/generators/mailer/mailer_generator.rb
/usr/lib/ruby/vendor_ruby/rails/generators/mailer/templates/
/usr/lib/ruby/vendor_ruby/rails/generators/mailer/templates/mailer.rb
/usr/lib/ruby/vendor_ruby/action_mailer.rb
/usr/share/
/usr/share/rubygems-integration/1.9.1/
/usr/share/rubygems-integration/1.9.1/specifications/
/usr/share/rubygems-integration/1.9.1/specifications/actionmailer-3.2.16.gemspec
/usr/share/rubygems-integration/2.0/
/usr/share/rubygems-integration/2.0/specifications/
/usr/share/rubygems-integration/2.0/specifications/actionmailer-3.2.16.gemspec
/usr/share/doc/
/usr/share/doc/ruby-actionmailer-3.2/
/usr/share/doc/ruby-actionmailer-3.2/copyright
/usr/share/doc/ruby-actionmailer-3.2/README.rdoc.gz
/usr/share/doc/ruby-actionmailer-3.2/changelog.Debian.gz