Apple Mail Privacy Protection (MPP), introduced in 2021, loads every image in an email, including tracking pixels, through Apple's servers as soon as the email arrives. The sender sees an "open" whether or not the person read it, and can't see their location or real IP address.
What it does to your numbers
- Open rates go up without anyone reading more, because every Apple Mail user counts as opened.
- Open-based decisions break: "send a follow-up to everyone who opened" or "this subject line won" can be driven by machine opens.
How to work with it
Judge cold email by replies and booked meetings rather than opens. If you keep open tracking on, use a tool that tells machine opens apart: mailzy keeps Apple's automatic opens in a lead's history but doesn't count them as opens or use them to trigger follow-ups. For subject lines, test against replies, and use the free subject line tester for the basics.