I do not know whether paypal provides IPN service. But I know that 2check and ikobo provide IPN service. I am an ikobo user. If buyer makes payment on my website, Ikobo will email me IPN information in no time. It is convenient. You can visit its website for more details.
I am using the service of ikobo.com and the specific feature for which i selected ikobo was its IPN service. You precisely need IPN intimation to activate the customer account so if you do not find it from paypal then you use ikobo.com for IPN service.
However, ikobo is slow in response to cutomer service. They claim that they have improved in their customer service but i still need to verify their claim as compared to their past negligence to provide timely support to their customers.