I am having the same problem. A paypal developer has written a great program you can download and use for free, plus the forum is great and will walk you through it, but IPN does not solve the issue of emailing the customer. I've been told you would need to add your own email code for sending email receipts.
Here is the link to the developer site message?board.id=ipn&thread.id=14078
Believe me its worth getting!