Any plugin to do Paypal to Autoresponder ?

Greetings,

I'm looking for what seems to be very simple but I cannot find it.

I'm looking for a plugin (or any other way) to make it so that :
1. visitor purchase something on my website using a Paypal button
2. visitor makes payment through Paypal
3. visitor is added to a list in my autoresponder system, so that I can follow up with instructions.

Trick is : The plugin must be working with any HTML form, cause the autoresponder I use (Cybermailing) is not one of the big names (AWeber, Mailchimp, etc).

Any idea of the best way to do that, and if a plugin could help with that ?

Thanks a lot in advance,
DJ

P.S : I'm pretty desperate cause I'm supposed to do a launch tomorrow, and since this week my regular payment and order manager crashed and is not reliable anymore (Murphy's Law). So I'm looking for a temporary solution, a quick fix. Any help would be much appreciated ! THanks !