collect_responses_from_templates

# File actionmailer/lib/action_mailer/base.rb, line 912
    def collect_responses_from_templates(headers)
      templates_path = headers[:template_path] || self.class.mailer_name
      templates_name = headers[:template_name] || action_name

      each_template(Array(templates_path), templates_name).map do |template|
        self.formats = template.formats
        {
          body: render(template: template),
          content_type: template.type.to_s
        }
      end
    end