We have another issue with the ASP.NET_MVC_Front_End not displaying an image.
Regardless of the value of HtmlOptions.IsResourcesEmbedded the image in the attached test email .msg file does not show because the url in the img element does not have the HtmlResourcePrefix in it:
I’d expect the source to be something like src="/document-viewer/GetResourceForHtml?documentPath=Aspose.Words.a9963580-1c8c-40ad-b05d-b2c68983c51e.001.jpeg"
This was reproduced from your demo app.
subject.zip contains the email file as subject.msg. email-no-image.png is a screenshot of the MCV web page with the missing image.
It works fine in image mode.