Windows has the following information about this MIME type. This page will help you find software needed to open your file. MIME Type: application/jsonDescription: UnKnownWindows does not recognize this MIME typeThis is the message some of my emails show when opened on outlook. Does it have anything to do with the images in my email being store in Amazon S3 Bucket? If so, where should I possibly pull my images from in email . Also please note that the images are being dynamically pulled via ruby code.