but in magento 1.9.1 the order notification email are available by default ?, because It does not work
I'm not sure whether I understand the question.
You mean in 1.9.1 is no order confirmation mail send after ordering?
Sure, there is a order confirmation mail send after the order took place. Are you sure you have an SMTP server installed? Check the logs and read Fundamentals for debugging a Magento store
Yes notification email are available by default but you may have do do some setup.
Do you have your cron running ? On the new magento version mails are send with the cron.
To set the cron with shell access (for linux ) you can do :
Then add one of these (the cron will run every 5 minutes :
*/5 * * * * /bin/sh /[magento_path]/cron.sh */5 * * * * /bin/bash /[magento_path]/cron.sh */5 * * * * /usr/bin/php /[magento_path]/cron.php */5 * * * * /usr/local/bin/php -f /[magento_path]/cron.php
More info here.
Hope this help you.