By default, when a customer buys something on my website (Magento 1.9) he receives an order confirmation via email. The thing is I'm using another platform to send my emails to the customer. So I don't want magento to send emails to the customer. I want to be the only one (the admin) notified when someone buys something.

So how can I make magento to send order email only to the admin and not the customer ? Maybe I have to modify some files, but I dont know which one...

I really need some help. Thank you !