I recently added a form for a book give away. Apparently this was not a very good idea, for now I am receiving hundreds of mails of people I am sure visited this page. I know this because there are hundreds of mails more than visits to this page, a mail is send every two minutes or so and the email addresses are all hotmail.com. So some robot or something is doing a very good job now.
Is there any way to protect me from this in the future?