For years, I've been constructing emails for my organization using Dreamweaver and using various email clients which accept raw HTML source to send to my distribution list.
This has worked fine until recently. Now, clients running iOS 15 or the latest macOS are unable to display my images regardless of the various privacy settings. Images in emails from other sources display propertly.
I link to images using the standard img ... src=http://... method. I tried https, but that had no effect.
The images are stored on my organization's website, which happens to be hosted by Bluehost. (Note it is NOT a WordPress site.)
Is there something I need to do on my website, etc. (some kind of security certificate?) which will allow iOS to display images?