I have been unable to get the IPN response to happen properly with the PayPal addon. I've called Media Temple and they say that cURL is available and can use HTTPS on their Grid Server. The PayPal email is the main one for the account (not just any one on the account). In PayPal the IPN says 'sent' . The IPN location is http://site.com/?page=gf_paypal_ipn. Payments in the GF admin just sit 'processing' no matter the status in PayPal.