instance method perform_delivery_sendmail

# File actionmailer/lib/action_mailer/base.rb, line 688
      def perform_delivery_sendmail(mail)
        sendmail_args = sendmail_settings[:arguments]
        sendmail_args += " -f \"#{mail['return-path']}\"" if mail['return-path']
        IO.popen("#{sendmail_settings[:location]} #{sendmail_args}","w+") do |sm|
          sm.print(mail.encoded.gsub(/\r/, ''))
          sm.flush
        end
      end