create_mailbox_file

# File actionmailbox/lib/rails/generators/mailbox/mailbox_generator.rb, line 10
      def create_mailbox_file
        template "mailbox.rb", File.join("app/mailboxes", class_path, "#{file_name}_mailbox.rb")

        in_root do
          if behavior == :invoke && !File.exist?(application_mailbox_file_name)
            template "application_mailbox.rb", application_mailbox_file_name
          end
        end
      end