Hello Claudia,
I have run some more tests in multiple devices and images are loading perfectly. Unfortunately, I am unable to reproduce the issue. Could you please ask the user to try to open the email in different network which is not part of the same private network so that we can remove the possibility that it is a network specific issue. Also, I have noticed that the images are being hosted in an external Image Hosting Service so, could you please upload the images into your Maropost account to see if it makes any difference.
I hope this helps.
Thanks!
