[netsharc]

To abuse the email system even more, wouldn't it be possible to add a header to the email with a base64 encoded image? I suppose with HiDPI, the image might need to have quite a high resolution. And then someone will find an exploit involving image decoding/displaying.. like one Outlook had years ago while parsing manipulated timestamps.

Edit: reading one example, the hosted image can be an SVG, so that would not be so heavy to be embedded into the header..

[teddyh]

Such standards exist already:

1. The ancient “X-Face” header: 48×48 black or white pixels: <https://en.wikipedia.org/w/index.php?title=X-Face&oldid=1220...>

2. The “Face” header, from 2005: 48×48 PNG image <https://quimby.gnus.org/circus/face/>