Autoresponder for paypal using data based

I need and autoresponder for my paypal account that when a client buy from me get a welcome email with the password each client has a unique password . i will provide the passwords so need and app to manage the password and clients emails get from the paypal payment email confirmation. I need this happend automatic when client make the payments on my paypal account. [login to view URL] a welcome email with the unique password [login to view URL] the system take the email from the paypal payment and take one password , so new client email will take a password from the data base [login to view URL] or webpage to manage all this passwords and clients emails that can be able to export to excel file.