PayPal Help Needed!

Whats up BHW!
I've got an issue here that i was hoping you guys/gals could help me out with. I am building a site selling legal documents for a friend but have run into a snag.

I need to harvest their Email address durring paypal checkout so that I can mail them a pdf that comes with their purchase. This PDF is not optional, it is manditory that they recieve it imeadiatly after purchase.

as it stands i have a paypal buy now button up but i cant figgure out how to get their email at the same time. After purchase they are redirected to a download/thank-you page but its my concern that i cant email them a follow up email with a link to the download page. if they close the thank you page they will never get the pdf which is crucial for delivering their product.

I really need to figgure out how to nip this in the butt before i start drawing traffic to the site.

Thanks for any & all advice you all can offer!!
-RR

Just put an input box on the thank you page saying "Please enter your e-mail address" and make sure that the download begins only after they've done that. That way, they would get the download right after payment and you would get their e-mail.

Thanks guys, I appreciate the advice.

@emailzapper- Lol thanks but Im not looking to hire a developer, this is a small scale website for a friend/family member. I probably should have mentioned in the OP that im not looking to sink any money into this site as its not one i intend to make any off of.

@renarssilters- My concern is the fact that some people may check out at paypal, land on the thank you page, than browse away from it expecting there to have been an email delivered to them (people are dumb). This would result in them not getting the pdf and not being able to recieve the package they just paid a few hundred bucks for.
I could not care less if the pdf is downloaded by non buyers, its only an information collection form. As it is i have placed a button in the sidebar for download but i feel that this is unprofessional and would like to figure out how to smoothly grab their email for delivery of a back up copy and a thank you email.
I dont even care about emailing these people after because they have just bought a 150-300 dollar package of legal forms, also its not my site and as soon as im done building it im not ever going to look at it again LoL


Again thanks for the replies guys, does anyone else out there have any suggestions?

You can use Contact Form 7 to gather whatever info you need and then redirect them to PayPal when they click submit. You'll get an email from the Contact form with the requested info.

Or you can put the form on your thank you page, so after they pay, PayPal will automatically redirect to the that page where you can say thank you and request their email. You can put the link to the download in the email2 version and have that sent automatically to them. This way no one has to manually send any emails.