Q: How to automatically email customers registration keys? I've written a bit of software that I'd like to share with others (a Mac Dashboard widget, specifically), but I'd also like to be compensated a bit for the time I spent on it. I've devised my own simple registration key algorithm, which takes a customer's email address and creates a 12-character alphanumeric key. The software itself is finished, demo limitations, key validation & all.
I just need to get the keys to customers. How do I simply alert a key generation script to automatically email a customer a key, upon notification that they paid my account? Can I use PayPal IPN & JavaScript?
The simplest solution will do - this is a five dollar widget. :)

A: i would use PayPal IPN plus PHP, then once paypal verifys it with your php script, it will send an email to the user, the other option is to use OpenCart, and have it so when people buy it, it will request you to activate the account, or have it automatically send it.
mail();

look that up on php.net :D
