At least on iOS, Mail Privacy Protection is designed to load all resources immediately upon receiving the email, not when viewing it. Maybe this still indicate

At least on iOS, Mail Privacy Protection is designed to load all resources immediately upon receiving the email, not when viewing it. Maybe this still indicates the email is valid to a spammer, but it wouldn’t show that you opened it (unlike i.e. Gmail’s image proxy, which only loads upon viewing.) https://www.litmus.com/blog/apple-mail-privacy-protection-for-marketers/ https://www.litmus.com/blog/apple-mail-privacy-protection-fo...