I'm sorry to hear you're having some difficulties with your not only downloading your email but how your email is displaying incorrectly in your email client. In order to thoroughly troubleshoot what is happening here please send us an email to social_support(at)constantcontact(dot)com with the following information:
If you had attempted to download your campaign from Constant Contact, unfortunately, we cannot set the page breaks when downloading the campaign as a PDF. It may be best to download your campaign as a PNG or JPEG file. We look forward to hearing from you and will follow up with you once we receive an email with the necessary information.