instance method enqueue_delivery

# File actionmailer/lib/action_mailer/message_delivery.rb, line 174
      def enqueue_delivery(delivery_method, options = {})
        if processed?
          ::Kernel.raise "You've accessed the message before asking to " \
            "deliver it later, so you may have made local changes that would " \
            "be silently lost if we enqueued a job to deliver it. Why? Only " \
            "the mailer method *arguments* are passed with the delivery job! " \
            "Do not access the message in any way if you mean to deliver it " \
            "later. Workarounds: 1. don't touch the message before calling " \
            "#deliver_later, 2. only touch the message *within your mailer " \
            "method*, or 3. use a custom Active Job instead of #deliver_later."
        else
          @mailer_class.delivery_job.set(options).perform_later(
            @mailer_class.name, @action.to_s, delivery_method.to_s, args: @args)
        end
      end