perform_delivery_sendmail

# File actionmailer/lib/action_mailer/base.rb, line 571
      def perform_delivery_sendmail(mail)
        IO.popen("#{sendmail_settings[:location]} #{sendmail_settings[:arguments]}","w+") do |sm|
          sm.print(mail.encoded.gsub(/\r/, ''))
          sm.flush
        end
      end