I have a server that hosts a website and some media files. If I try to embed an image from my server into an html email using img tag:
<img src="https://www.example.com/media/hello.jpeg">
In email clients like yahoo and rediffmail, image fails to load. The image loads perfectly when opened in Gmail or separately in a browser. Even in yahoo, when composing the email, the image loads fine but after sending the mail, the image does not load. When a mail is received on yahoo, image does not load at all.
If I embed an image from a different server, the image loads fine in all email clients. Since yahoo uses image caching, I'm not able to diagnose the problem. The browser console shows 502 bad gateway error for the yahoo image cache url.
When I check the nginx server logs, I don't see any requests from yahoo origin trying to access the image. There are requests from gmail origin.
