On September 20, 2021, Apple rolled out Mail Privacy Protection (MPP) for their mail app on iOS 15, iPadOS 15, and macOS Monterey devices. Since then, the Omeda team has been testing Mail Privacy Protection and keeping a close eye on email data to determine how total open rates would be affected. In January, we released our analysis showing the impact of MPP after three months. Now, six months later, we have an updated picture of MPP’s impact.


What is Mail Privacy Protection & How Does it Work?

To review, Mail Privacy Protection (MPP) ​​stops email senders – like Omeda – from using invisible tracking pixels to collect information about the user. When Mail Privacy Protection is enabled, Apple’s proxy servers will download a pixel when the application is opened and the mailbox is updated. This pixel download then indicates to Email Service Providers (ESPs) like Omeda that the email has been opened.  

This new feature helps users prevent email senders from knowing when they open an email. It also masks their IP address so it can’t be linked to other online activities or used to determine their location.

If a user were to turn on this feature, we can no longer accurately show an “open” from someone who is using the Apple Mail App to view emails. In fact, initial tests showed the possibility of open rate inflation.


Omeda’s Initial Test Results

Our initial tests before the wide rollout of MPP showed that open rates were inflated for clients with recipients using Apple Mail on an iOS device that has been updated to iOS 15 and have opted-in to the Mail Privacy Protection feature. For the full details and findings from our initial tests, read this blog.

What the Data Shows, 6 Months Later

Now that Apple’s MPP has been up and running for six months, we wanted to see if the results we saw in our analysis from three months ago still holds true, or if the picture has changed. Previously, we analyzed 60 days of email data from before the rollout of MPP to 60 days of data after the rollout. This time, we decided to look at an even earlier time period (5/19/21 – 7/18/21) to confirm our “before” data was reliable, and we also pulled two new “after” time periods (11/27/21 – 1/26/22 & 2/1/22 – 3/3/22) to see how the open rate data was trending.

As expected, we again see that unique and total open rates were impacted; however, we are now seeing a much larger impact compared to what we saw three months ago. In fact, we are now seeing open rates at nearly DOUBLE what they were prior to the rollout of MPP.

In the chart below, you’ll see the date ranges of the data collected and the impact of MPP:

Metric – All Sends5/19/21 – 7/18/21
(Before MPP)
7/19/21 – 9/17/21
(Before MPP)
9/27/21 – 11/26/21
(After MPP)
11/27/21 – 1/26/22
(After MPP)
2/1/22 – 3/3/22
(After MPP)
Delivery Rate98.6%98.5%98.2%98.6%98.6%
Total Open Rate22.6%22.4%27.3%37.5%40.5%
Unique Open Rate15.2%15.2%19.1%26.6%29.0%
Total Click Rate2.3%2.4%2.1%2.4%2.4%
Unique Click Rate1.5%1.6%1.4%1.6%1.6%
Total CTR10.1%10.8%7.6%6.4%5.8%
Unique CTR10.0%10.5%7.2%5.9%5.4%

The chart above reflects the impact of Apple’s Mail Privacy Protection before and after its release.

A note on email volume: These ranges include approximately 80,000 deployments both before and after the introduction of Apple’s MPP, and about two billion emails sent during both timeframes. At these high volumes, we’re able to more accurately identify trends and understand the full impact of MPP. 

The most relevant data points in the chart above are the unique and total open rates. When comparing the “before” data to our most recent “after” time periods, we found that both the total and unique opens rates have nearly doubled. After three months, we were seeing modest open rate increases of 4-5 percentage points. But now, after six months, we are seeing total open rates up nearly 18 points (22.6% to 40.5%), and unique open rates up nearly 14 points (15.2% to 29.0%).

We expected to see open rates rising as a result of MPP and for open rate data to become more distorted over time. However, we were surprised to see such a large increase over the last three months. This likely indicates that many more recipients have upgraded their devices to iOS 15 and have opted into MPP, and that the MPP adoption rate is continuing to increase.

The large increase could also indicate our clients are still heavily relying on open rate to measure engagement and target their audience. Now more than ever, open rates can’t be trusted, and any data – such as click through rate (CTR) – that utilizes the total open rate data is NOT as reliable as it was in the past. We recommend using alternative metrics, like clicks, to measure engagement. Furthermore, any email automations that are using opens as a trigger should be reviewed and adjusted.

Now, for the good news: Total click and unique click rates are valid and not impacted by MPP. In fact, these numbers have leveled off and returned to their “before” MPP state. The major impact is on open rates, not click rates.

Below, you’ll find a deeper view into the data, broken down by email content type:

Content TypeDate Range
(Before & After MPP)
Total Open RateUnique Open RateTotal Click RateUnique Click RateTotal CTRUnique CTR
Third Party & Advertiser5/19 – 7/18

7/19 – 9/17


9/27-11/26

11/27 – 1/26

2/1 – 3/3
21.3%

20.9%

26.0%

36.4%

40.3%
14.8%

14.7%

18.6%

26.5%

29.3%
0.8%

0.9%

0.7%

0.8%

0.8%
0.6%

0.7%

0.5%

0.5%

0.6%
4.0%

4.3%

2.8%

2.1%

2.0%
4.4%

4.8%

2.9%

2.0%

2.1%
Audience Dev & Circulation5/19 – 7/18

7/19 – 9/17


9/27-11/26

11/27 – 1/26

2/1 – 3/3
21.4%

21.5%

26.3%

34.5%

38.0%
14.3%

14.4%

18.2%

24.4%

27.3%
2.0%

1.8%

1.7%

2.1%

1.8%
1.6%

1.4%

1.3%

1.6%

1.4%
9.4%

8.4%

6.4%

6.0%

4.6%
10.9%

9.9%

7.3%

6.6%

5.0%
Digital Magazines & Reader Service5/19 – 7/18

7/19 – 9/17


9/27-11/26

11/27 – 1/26

2/1 – 3/3
23.9%

23.5%

27.5%

35.9%

38.6%
14.8%

14.6%

17.9%

23.6%

25.8%
2.4%

2.3%

2.2%

2.4%

2.6%
1.7%

1.7%

1.6%

1.7%

1.8%
10.1%

9.8%

8.0%

6.7%

6.6%
11.8%

11.5%

8.9%

7.2%

7.2%
Events & Virtual Conferences5/19 – 7/18

7/19 – 9/17


9/27-11/26

11/27 – 1/26

2/1 – 3/3
19.9%

18.6%

23.9%

33.3%

35.2%
13.6%

13.0%

17.1%

23.9%

25.5%
0.7%

0.7%

0.6%

0.7%

0.8%
0.5%

0.5%

0.4%

0.5%

0.6%
3.3%

3.7%

2.6%

2.0%

2.4%
3.4%

3.9%

2.6%

1.9%

2.5%
Marketing & Other Products5/19 – 7/18

7/19 – 9/17


9/27-11/26

11/27 – 1/26

2/1 – 3/3
18.4%

17.9%

23.7%

33.9%

36.4%
13.1%

12.8%

17.3%

24.7%

26.7%
1.1%

1.1%

1.0%

1.1%

1.1%
0.9%

1.0%

0.9%

0.9%

0.9%
6.1%

6.4%

4.4%

3.4%

3.0%
7.2%

7.5%

5.0%

3.7%

3.4%
Enewsletters5/19 – 7/18

7/19 – 9/17


9/27-11/26

11/27 – 1/26

2/1 – 3/3
25.2%

25.2%

29.8%

39.7%

43.2%
16.5%

16.7%

20.4%

27.8%

30.6%
3.4%

3.6%

3.1%

3.3%

3.4%
2.1%

2.2%

1.9%

2.1%

2.1%
13.4%

14.4%

10.5%

8.4%

7.9%
12.8%

13.4%

9.5%

7.4%

6.9%
Research & Surveys5/19 – 7/18

7/19 – 9/17


9/27-11/26

11/27 – 1/26

2/1 – 3/3
20.0%

17.6%

23.3%

32.1%

32.2%
14.2%

12.5%

16.8%

23.7%

24.0%
1.3%

1.0%

0.7%

0.9%

1.0%
1.2%

0.8%

0.6%

0.7%

0.9%
6.7%

5.4%

2.9%

2.7%

3.1%
8.1%

6.5%

3.4%

3.0%

3.6%

The chart above reflects the differences by content type before and after Apple’s Mail Privacy Protection release.

Below you’ll find definitions for how the data in the charts above were calculated:

MetricCalculation
Delivery RateDelivered / Sent
Total Open RateTotal Opens / Delivered
Unique Open RateUnique Opens / Delivered
Total Click RateTotal Clicks / Delivered
Unique Click RateUnique Clicks / Delivered
Total CTRTotal Clicks / Total Opens
Unique CTRUnique Clicks / Unique Opens

The chart above defines how each metric is calculated.

Guiding You Through MPP

First Things First: As mentioned above, we recommend that clients use alternative metrics besides open rates to measure engagement. Concentrate on metrics beyond open and sent insights, and dive further into conversion metrics and other ways that advertisers/sponsors are measuring campaigns.

Continue to develop your audience and first-party data to go beyond just an email address, so you are prepared when tracking capabilities are impacted. By understanding who your audience is and what they are looking for, you can deliver valuable multi-channel interactions to help ensure the right message is delivered to the right person at the right time.

Check Out New Reporting Options: Omeda offers reporting to help clients understand the impact of Apple Mail opens in their deployments. Apple MPP opens are displayed in the Opens by Client and Device Reports, and they can be selected in the Email Client section in Audience Builder. The opens that are likely to be from those who have opted into MPP are listed as “Mozilla/5.0” instead of within the Default Browser section. Learn more about this here.

Review Email Marketing Strategies: We recommend reviewing this blog post, written by Omeda’s email marketing experts, which outlines 10 email marketing strategies that specifically help to address the challenges presented by MPP, including using behavioral-based segments, cleansing your database, A/B testing, and more.

Additional Ways to Pivot Your Strategy: This excellent resource from Brief Media outlines 5 additional ways to pivot now that MPP is officially here, such as establishing KPIs beyond open rates and keeping lists healthy.


The Omeda team will continually monitor the impact of MPP and provide ongoing updates. We expect that as Apple MPP adoption rate nears the market saturation point, we’ll be able to provide a more definitive analysis in the coming months. As needed, we’ll release additional enhancements to query data for the most accurate insights into email marketing performance.

For more information about how to navigate through Apple’s Mail Privacy Protection, contact your Omeda Customer Success Manager or reach out to sales@omeda.com.