Newsletter Images Not Displayed in MacOS, iOS Mail

Newsletter email images are not displayed when viewing the email in MacOS, iOS, iPadOS. If the email is viewed in a web browser via the “View this in your browser” link, the images are displayed. The images are displayed when the email system is accessed through a web browser and in Outlook. In MacOS and iOS, the image is displayed as a broken link and there is NO option to load/download the image as in Outlook. Even the MailPoet logo is displayed as a broken link.

I have completed all the recommended steps in https://kb.mailpoet.com/article/370-images-not-displayed-in-emails.

1. Hotlink protection has been turned off
2. Folder permissions verified
3. Not using Google
4. Apple Mail privacy setting for “Load remote content” is turned off. The message “Unable to load remote content privately” in NOT shown in the email.
5. The domain passes the blacklist check

Additionally, the email passes the SpamAssassin test with a score of 9.9.

When the raw source of the email is viewed where the images are shown as broken links, the image URLs can be copied and pasted into a browser and they display correctly.

I would appreciate any further suggestions on how to remedy this ongoing problem.