Will new privacy networks change engagement metrics?

You've probably already felt this one. Ever since Apple Mail's Mail Privacy Protection (MPP) launched, open rates have looked suspiciously high for a lot of senders. That's not your list suddenly loving you more. It's Apple pre-fetching tracking pixels on behalf of users, which makes every Apple Mail open look like a real one even when the email was never actually read.

And MPP is just the start. Browser-level privacy tools, VPNs, and privacy-first networks are slowly eroding the third-party tracking signals that email metrics have leaned on for years. The trend isn't going away.

So what does that mean for your numbers? Here's the honest breakdown.

Metrics that are losing their reliability:

• Open rates are already compromised for Apple Mail users (which is a big chunk of most lists). Treat open rate as a directional signal at best, not a precise measure of actual reads.
• Click-to-open rate (CTOR) gets skewed whenever open counts are inflated. If your denominator is wrong, the ratio is wrong.
• Device and location data from opens is increasingly unreliable. Apple's proxy servers mask real device data.

Metrics that still hold up:

• Clicks are still meaningful. A real click is a real action. Attribution can get messy at the conversion stage, but the click itself tells you something.
• Conversions and revenue tied to email campaigns. If someone buys after clicking, that's a signal worth tracking.
• Reply rates and direct engagement (survey completions, form fills) are impossible to fake. They're also underused.
• Unsubscribe and spam complaint rates. These are negative signals, but they're real ones. They reflect how your audience actually feels about your email.

The shift that matters here is moving away from first-party data versus third-party data. Clicks, purchases, replies, and form submissions are data your subscribers generate by taking a deliberate action. That data doesn't rely on a pixel being loaded or a tracking script running in the background. It's yours, and privacy changes can't take it away.

Practically speaking, here's what to adjust now rather than later. Stop reporting open rate as if it were the primary health signal for your list. Start reporting on clicks, conversion events, and revenue per email sent. If your ESP's engagement scoring still leans heavily on opens to determine who's active (and many do), you'll want to layer in click and purchase history before you act on any re-engagement or suppression decisions.

One more thing worth knowing: some senders have actually found this shift clarifying. When you stop optimizing for open rate, you start optimizing for what you actually want people to do. That tends to produce better email. (Of course, explaining that to a stakeholder who loves seeing a big open rate number is a different kind of challenge.)

Want to see how your current setup looks from a deliverability angle? Our free Email Header Analyzer can help you read what's actually happening when your emails land. Or if you're rethinking your whole measurement approach and want a second opinion, our SOS hotline is free.