Is there something done to help to do the following?

At any rate, when someone comes to the site, they’ll enter their name and email address for a ‘free document’.  We automatically send them an email right then with this document (maybe a pdf), so their email address must be correct.  This email or PDF has a link to another site where they might buy something.  If they do buy something, we should remove them from the next two steps:  1)  A few days after the immediate email, they get an automatic follow up email from us.  2)  Then about a week later, they get another automatic email, giving them another chance to follow the link and buy.  They must have the ‘unsubscribe’ or ‘opt out’ option on all the emails we send to them automatically (it’s required by law).