Recently I noticed that some of the images in email updates received from the community forums were broken in Gmail.
After a bit of research, I found the issue to be Cloudflare WAF rules. Specifically rules 100201 and 100201_2. (However, other rules may be affected for other email clients)
To resolve I had to add the list of Google’s IPs to the WAF allow list. You could also just disable the rule, but that would also disable any protection that the rule offered.
You can find a list of Google’s IPs here:
As mentioned you may have to repeat this for other 3rd party proxies/CDNs because there are rules for others beyond gmail’s googleusercontent proxy (google image cache) as well:
I’m posting this in case anyone else noticed and also for anyone else out there with this or a similar Google proxy issue.