[xyzzy_plugh]

I'm guessing if you used a popular web-based email service, or any browser email client, then this would be possible.

[klapinat0r]

Possibly, but you'd still have to (try to) "render" it in your browser by opening the mail.

On a similar note, your web mail could fetch images in emails ahead of time, but that would still be out of your browser's context

[degenerate]

Remember...... 2008. Many people still had "auto download pictures" enabled in their email.

[raphar]

note that the url is inside an <IMG> tag.