Thanks for reaching out in the Community regarding this issue. We know how important it is to have your email show up like you expect it to.
If you can, please email us at social_support(at)constantcontact(dot)com with your username, the affected campaign name, a screenshot of the issue and a reference to this post and we will do some additional research on this to hopefully prevent the issue from returning in the future for you.
I did notice on your account that you are using the Legacy editor for some of your emails, you may want to consider using our latest editor for all of your campaigns.
Thank you. I sent you an email with screenshots per your request. FWIW, this is a problem with the new editor...the Legacy editor was fine and didn't create these "spacer" issues.
Thank you for giving us this update! We have a received your email with these details. A member of our Support will be reaching out to you directly with any further information.