[someweirdperson]

> I think what is happening is that Apple Mail prefetches all images when the email is received (over a privacy-preserving proxy).

How does this privacy-preserving work, where the leak is the specific resource being read?

[zwily]

Doesn’t leak your IP address. It also doesn’t tell the server you opened the email, or when you opened it, because it always fetched them whether you open or not.

Basically all the server learns is that the email address went to an Apple Mail client.