You can do most of this relatively easily if you are willing to work with PayPal. They have a thing called Instant Payment Notification for async notification of purchases. If you give PP yr cart functionality, then you have to write an IPN handler, which is a bit of a PITA, but then the temp download link and email notification are pretty easy.
1. PayPal is ugly.
2. PayPal are bastards.
― ShamPowWow (libcrypt), Thursday, 8 January 2009 02:37 (sixteen years ago)