[otrs] Closing email

Hi, I would like to send an email with information to a customer when his/her ticket is closed. I have create an "Automatic Reponse" with type "auto reject". But, it does not work. How can I do this ? Initially, I wanted to send a first email X days after agent's last response to inform the customer that his ticket will be closed. Then Y days later I really close the ticket and send a closing ticket email. Is it possible to do so ? Regards. Eric Boudrand http://www.thegreenbow.com