Apple’s Mail Privacy Protection update: One year in the books

Here’s what we’ve seen, what we’ve learned, and how we’ve responded.

On June 7, 2021, at the annual Worldwide Developers Conference (WWDC), Apple previewed a slew of new updates that included changes to its Intelligent Tracking Protocol (ITP) and Mail Privacy Protections (MPP), which began to rollout in September 2021.

While past changes had been primarily focused on tracking web and physical location of users, Apple’s shift to focus on email—particularly metrics driven by pixel-driven opens—was a significant expansion of the type of activity that Apple seeks to hide. Email marketers have relied heavily on open rates to track user interest, adhere to best practices. ESPs have also used OR's as a metric to help monitor and enforce network-level compliance standards.  

At the time, we made several predictions as to what this change would mean for email marketers. Let's see how we did. 

Prediction: Your email list will be affected, so don't only rely on open rates

The prediction for this rested on two factors:

  1. The percentage of your list that is opened in the Apple Mail app
  2. The percentage of those users who would choose to opt-in to Mail Privacy Protection

Because of the subtle tactics Apple took in the opt-in process, we predicted that “it’s best to assume that 100% of your Apple Mail users will select Mail Privacy Protection upon completing the update.”


As of August 2022, MPP has experienced about a 90% adoption rate.

What that means for you

Adoption has peaked, indicating nearly all Apple users have made their decision. Recent open rates can now act as the new stabilized benchmark.

In the graph below, the teal line represents iOS15. Right around Black Friday, iOS15 surpassed iOS14 in terms of adoption and has continued to rise after the holidays as new devices were either purchased or updated.

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Prediction: Subject Line testing will be affected

“Unknown opens” will skew results for Subject Line (SL) tests, so it’s best to learn as much as you can before it takes effect.


SL testing is still a valid approach to optimization.

What that means for you

  • As long as audiences are chosen at random, MPP impact should be consistent across test groups
  • Subject line testing results are still valid based on observed datapoints from Epsilon’s native reporting

Prediction: Click rates will be a “better metric”

Unlike MPP making it appear that Apple Mail app users opened emails they really have not, the click rate is not the same—meaning MPP won’t make it appear that users clicked something they have not. Clicks won’t be falsely recorded, so they will remain a strong metric for performance evaluation.


Clicks have remained unaffected throughout the Apple MPP rollout.

What that means for you

As an industry, we need a new approach to measurement so we can look beyond opens and dig into more holistic forms of engagement measurement across the communication touchpoints, such as conversions, site or app visits and, of course, clicks.

Recommendation: Shift measurement to leverage click data as main source of true engagement indicators as it becomes the main trusted user action.

Prediction: Personalization by IP will be a challenge

Live content based on time-of-open, geolocation, IP and devices already a required a fall-back experience when support is limited. Apple’s MPP update would only exacerbate those challenges, leading to less accurate targeting, measurement and a poor customer experience.

Brands will need to adopt new means by which to track user behavior and serve targeted ads and emails—one that relies on first-party data and is privacy complaint.


We nailed the prediction. 

What that means for you

Email marketing has long been a consent-based channel, and yet, marketers could use other non-consensual (or loosely consensual) signals to personalize email communications.

Although Apple has forced their hands, MPP encourages email marketers to get back to their consent-based roots and gather first-party data to activate personalized experiences. A strong identity resolution solution built on a foundation of concrete first-party data and resilient identifiers such as name and postal address—not IP addresses or cookies—will be a future requirement for marketers.

This has made AI and Machine Learning are more valuable than ever. If you’re not leveraging intelligent personalization in your emails by delivering offers and content tailored to audience preferences, now is the time to start.

Prediction: Opens will be inflated

Saved the most obvious for last. Yes, MPP means any delivered email to a user who has enabled MPP will always render an email send as opened, regardless of whether the user actually viewed the content.


ESP's handled this issue differently. Some ESP's continued to count the MPP “opens,” resulting in inflated open rates. In these cases, new benchmarks were set.

Epsilon made the decision not to count automated opens in standard reporting, as they are not representative of true user interactions—ingesting insincere data is problematic on its face.

What that means for you

With Epsilon’s approach, new means of measurement were created, like identifying false MPP opens and removing them from valid events. While MPP opens are suppressed, they are still accessible, giving our clients the ability to identify and target the impacted audience for greater accuracy in reporting and audience selection purposes.

Epsilon leverages in-market signals to estimate true open rates, which can help marketers monitor how their opens are trending. This is extremely helpful for our clients who prefer to keep reporting consistently to executives.

A bit about future-proofing measurement...

Epsilon continues to identify insights by evolving our strategic approach to measurement. Even before MPP was announced, we removed bot opens from measurement. With MPP’s rollout, we augmented this process to estimate ‘true’ open rates by leveraging customer signals.

But email, as a consent-based marketing channel, is more valuable than an open: Email drives loyalty and conversion. It builds stronger relationships by meeting subscribers where they are with the content they want. From the billboard effect to the “package delivered,” asking if a subscriber opened an email was always a superficial measurement of the value of an email.

Epsilon has been refining measurement weighting to account for true channel success: Engagement. But engagement insights certainly don’t jump off the—unless you know how and where to look!

Epsilon’s Performance Insights tool, which includes Privacy Insights, equips users with the data they need to make better informed email marketing decisions in a post MPP world.

So, how’d we do?

Long story short: we got it right and the sky didn’t fall. Phew.

Long story long: Our prediction was an OR drop of about 40%. July 2021 vs. July 2022 showed a drop of nearly 37%. Pretty darn close.

There are a number of factors that likely caused us to be off by 3% in our prediction, including some verticals augmenting the trends. However, the click rate has not changed at all, so we can count on the accuracy-at-scale of our reported open rate impact.

Here's how you can responding effectively to Apple's MPP update

We’ve already covered derived opens, but there are other strategic pivots that brands can implement in order to turn this challenge into an opportunity.

Here are some best practices to consider:

  • Ensure creative is highly engaging and encourages users to click
  • Develop a direct re-engagement campaign for the inactive MPP audience to click to confirm their subscription before falling off the list
  • Consider extending the “active” window for MPP users only
  • Update non-opener segmentation to suppress any users who have clicked
  • Consider adjusting subject lines and creative for redeployments for MPP users
  • Adjust rules & strategies to avoid MPP users inadvertently entering inactive streams

Now that you’re ready to tackle Mail Privacy Protection’s impact on your marketing program, here’s what Apple has announced is coming next >