Hello @MarcoR67 ,
After looking at a few of your email newsletters they appear to be just a single image maxed out full template width. When sending an email that only contains an image, if the recipient does not have “enable external images” turned on the email would appear to be blank for them. This is ultimately a setting within their particular email client’s inbox that you would have no control over unfortunately. One suggestion would be to include other blocks around the image block itself. Placing a button underneath that would click to view full pdf document so that way if the image doesn’t show they have a call-to-action button that would read something like “click to view document” allowing them to see it that way. I have also provided a link below to one of our knowledge base articles discussing this further for you.
https://knowledgebase.constantcontact.com/articles/KnowledgeBase/17661-avoiding-image-only-emails
... View more
