Content × Advertising
Apple MPP and the open-rate problem
Why open rates lost their meaning, and what to track instead.
For years, the open rate was the golden metric of the newsletter industry. It dictated sponsorship rates, defined subscriber engagement, and measured campaign success.
Then came Apple's Mail Privacy Protection (MPP).
First introduced back in 2021 with iOS 15, MPP fundamentally broke how the email industry tracks engagement. If you are still buying or selling newsletter sponsorships based entirely on open rates, that strategy needs to change. Here's why.
What does MPP do?
Mail Privacy Protection is an opt-in feature for Apple Mail app users. When enabled, Apple automatically pre-fetches and downloads email content behind the scenes, including the invisible tracking pixels used to monitor opens. Because Apple's proxy servers download this data automatically, your email platform registers a legitimate open, regardless of whether a human being ever looked at the message.
Direct impact on newsletter advertising
- Inflated open rates and flawed CPMs. With over half of typical subscribers using Apple Mail, overall open rates are artificially inflated. Advertisers buying sponsorships on an open-based CPM (Cost Per Mille) model are often paying a premium for impressions generated by proxy servers rather than actual readers.
- Programmatic ad revenue drops. To maintain ad quality, programmatic ad networks frequently filter out MPP-triggered impressions from their reporting. Consequently, a newsletter might boast a stellar 55% open rate but see unexpectedly low programmatic impressions and payouts.
- The loss of location-based targeting. MPP obscures the recipient's true IP address. This makes traditional email geotargeting highly unreliable for local newsletters or regional ad campaigns.
How to adapt your strategy
MPP does not break newsletter marketing; it simply breaks open-rate tracking. Clicks and conversions remain completely real. Here is how top-tier publishers and advertisers are adapting:
- Make clicks your north star. Shift focus to Click-Through Rate (CTR). A click requires intentional human action that Apple's servers cannot replicate. Advertisers should demand historical click data rather than vanity open rates.
- Restructure sponsorship deals. Move away from open-based CPM pricing. Transition toward CPC (Cost Per Click) models, flat-rate sponsorships, or hybrid structures.
- Collect first-party data. Since IP-based geotargeting is compromised, gather zero-party and first-party audience insights directly. Use polls, welcome workflows, and subscriber preference centers to segment your list by location and intent.
The newsletter industry remains an exceptionally high-ROI advertising channel. However, success now belongs to the operators who stop selling vanity metrics and start selling verifiable human intent.