I am new to Otrs and have it almost setup the way we wanted with help of the various faq and online resources, i can't however get one thing to work and hope you can help me out with it

If an customer sends a new email message for help, the ticket is created in otrs but otrs doesn't send an automatic confirmation email. I want to auto respond with an message like: thanks for contacting our helpdesk, your ticket is created with number ... and we will contact you as soon as possible (or something like this.)
Email itself works as i can reply manual to created tickets, but i want it to auto respond...
Can anyone help or guide me to configure this last step ??