There is another closed thread on this issue; https://community.constantcontact.com/t5/Need-help-with-something-else/Lines-on-sent-email/td-p/3014... but Support seem to have helped with it.
I am having the same problem and I've moved about the images/ blocks, and if I get rid of one line another seems to appear elsewhere.
Hope someone can help!
We're very sorry to hear that lines are appearing in your email campaign as well. We are tracking this in customer accounts and our engineers are working as quickly as possible to get it resolved! We do know that this seems to be happening with email marketing templates from all email marketing companies. Nevertheless, in some cases, combining multiple blocks into one block will reduce the number of lines. Another workaround would be to match the Outer Background color of your email campaign with the Inner Background color. In your email campaign, click Design to change the background colors:
Is there any resolution on this issue yet? I am still getting lines and making the inside and outside of the email the same colour does not work for my emails.
Thank you for your response!
We are happy to look into this issue for you. Would you kindly send and email to social_support(at)constantcontact(dot)com with your username and a reference to this post?