Campaigns include inappropriate links like "Edit" linking to the node/edit page. And if you are embedding a view, then the link "Edit view" is included in the email.
Note that the preview page does not have the problem.
Turning off the Contextual Links module entirely solved the problem. However, it would be better for MailChimp Campaigns to play nicely with that module, especially since it is in core and is so handy.
Thanks for all the great progress on this module.