Images are missing in the e-mail notification

Everytime you receive a notifitcation with an image, all the images are missing if you read the e-mail in a desktop client (Outlook, Apple Mail).

They are not displayed.

Our suggestion is, that because of https, the e-mail client can not retreive (load) the images.

If you open the same notification in a web client (Google Mail, iCloud) - even when forwarded- and you are logged in at the same time in Confluence, then the images will be loaded.

Our readers (especially from blog posts) are annoyed from the missing images.