[mmh0000]

Some of the big providers already do this, notably Apple and Gmail:

https://www.litmus.com/blog/gmail-prefetching-images

[londons_explore]

Gmails prefetch is terrible for privacy because it honors http cache headers, which means tracking companies simply use a "no-cache, must-revalidate" header to defeat it.

[hedora]

That sounds like a feature, not a bug, given where Google’s revenue comes from.

[RobotToaster]

Which is completely stupid since images in an email should never change.