I've composed an email in HTML that has an image in it.
The image "src" attribute has a URL pointing to a controller action endpoint on my server (ASP.Net) which returns a FileContentResult.
An example of the img tag looks like this:
<img src="https://www.mywebsite.com/controller/action?argument=value" width="600" height="300" alt="HeadingImage" title="HeadingImage">
The email displays as expected in Outlook.
If I take the source from Outlook and just view it in Chrome desktop, it still works fine.
If I visit the img URL in Chrome the image is downloaded.
However, if I view the email in Gmail the image does not display. Why might this be the case? I get a single error in the console looking something like this:
ci6.googleusercontent.com/proxy/<SNIP>https://www.mywebsite.com/controller/action?argument=value GET https://ci6.googleusercontent.com/proxy/<SNIP> 404 ()