I have no idea how to confirm a PayPal payment was made in a safe way that can't easily be hacked by any basic user into falsely confirming the payment. As such, I manually confirm each PayPal payment email which means customers have to wait sometimes several hours before getting their digital order which should be delivered instantly. How can I confirm in a safe unhackable way that a payment was in fact made so I can provide instant delivery? I programmed my entire checkout system myself in ASP so I'd want a method that would work with my self made system. Thank you
Well i guess using some sort of API , will help you, if you are using some nice CMS, like WHMCS, etc they have that function already
There is in API for this function , installing this API is depend in which type of script are you used.