Later this month, we expect to see Apple release the latest versions of their operating systems, iOS 15, iPadOS 15, macOS Monterey, and watchOS 8. Users who upgrade their Apple devices to the latest versions will be able to use a feature called Mail Privacy Protection. When this feature was first announced, we published a blog post answering many of the frequently asked questions on Mail Privacy Protection (MPP) and its potential impact on your email program.

With the release date (likely mid-September) rapidly approaching, we wanted to offer a number of ways in which you can prepare for MPP and an update on the steps Twilio SendGrid is taking to help you manage what will likely be a significant change to the way you track your email programs.

A quick recap on MPP

Users that have iOS 15-enabled Apple devices and the Mail App will receive a prompt to opt-in to Apple’s Mail Privacy Protection feature. This will be available to iPhone, iPad, and Mac users. Apple Mail application users can configure any inbox to the application, so this is not specific to Apple domains, but rather any domain (including Gmail, Microsoft, etc.) configured to the Apple Mail app. 

The technical details of how Apple will accomplish this are not entirely clear and could change, but results from beta testing analysis suggest that Apple will be pre-fetching the content of all messages delivered to mailboxes configured to the Apple Mail application.

When Apple pre-fetches the content of the email they also fetch remote images which include open tracking pixels (small, transparent images that tell you when a recipient opens an email, a staple of email marketing for more than 2 decades).

Every message you send to an Apple Mail user with MPP enabled will look like it has been opened.

What this likely will mean is that every message you send to an Apple Mail user with MPP enabled will look like it has been opened (whether or not the particular message was actually opened by that user).

This change renders open tracking futile for any recipients who opt into MPP—it means that senders who routinely rely on open tracking to better tailor their email programs lose valuable insight into how recipients are engaging with their emails. 

How to prepare for Mail Privacy Policy

Get comfortable with clicks

With the possibility of open data becoming less reliable, it is critical that you think about alternative ways to measure the performance of your email program. The most obvious replacement for open data is click data.

Use click activity as your primary indicator for engagement with your email program.

Even before MPP was announced, a good case could be made that click data is a stronger, more reliable signal of positive engagement than opens. Clicks are intentional and, therefore, a cleaner signal of engagement. 

MPP will almost certainly end the debate. Now is the time to get serious about using click activity as your primary indicator for engagement with your email program. To transition to clicks as your main engagement metric, consider:

  • Using clicks for your engagement-based sunsetting policies instead of opens. 
  • Using clicks to measure the performance of your A/B tests.
  • Building benchmarks for your click rates. Dig through historical data to orient yourself with your current click metrics. Keep in mind that click rates are always going to be lower than open rates. 
  • Replacing open rate with click rate in any reports or dashboards you frequently review or present.

Prepare more regular re-engagement campaigns

For more than a decade, senders have used engagement recency to determine when to send a re-engagement campaign. For example, if a recipient hasn’t opened or clicked a message in six months, you might send them a re-engagement campaign to see if they still want to receive your mail. If they don’t click the re-engagement message, they are removed from your mailing list. 

It is time to rethink this strategy. You can still rely on clicks as a reliable signal of positive engagement. If someone is clicking, consider them engaged. However, if your data shows that some recipients open every message, but never click, this should be your new signal for non-engagement.

Because clicks are harder to come by, and some messages might legitimately be opened, but not clicked, it will become more important to nudge your users to take an affirmative engagement action. More frequent re-engagement campaigns are a good way to do this. Take a look at this blog article for examples of successful re-engagement campaigns. 

Increase the use of CTAs to drive more clicks

As we already mentioned, clicks are harder to come by when compared to opens. But, you don’t have to remain passive here. There are things you can do to encourage more click activity and increase click rates. One easy step is to develop shorter, more concise emails with fewer, but more prominent calls to action. 

Develop shorter emails with fewer, but more prominent, calls to action.

This isn’t a new idea, but it will become more important as open rates become a less reliable signal of actual engagement. The added benefit goes far beyond giving you more engagement data.

When done correctly, getting recipients out of the email and onto your website or into your application allows for much richer, customizable experiences. You have far more options at your disposal on a webpage or in an application than you do in an email. It also goes without saying that websites and smartphone applications are where people spend money. It really is a win-win.

Check out our guide on CTAs for more information on creating action-oriented emails.

Audit your open-based workflow automations

Workflow automation has been an exciting development in the email world over the past 10 years or so. There are countless out-of-the-box or custom-built workflow automation tools out there. Most, if not all, of these tools use email engagement data to automatically determine what and when to send the next message. 

If a significant portion of your email is opened automatically by MPP or similar features, this will not only disrupt your workflow automation, it could also result in some very bizarre experiences for your recipients. Over messaging your recipients based on MPP opens could become a reality if your triggers are based on open patterns or engagement based on opens. 

Now is the time to audit your workflow automations that rely on open data to trigger or schedule email sends and adjust the workflows to use clicks instead. Ask yourself, “What would this automation look like if every message looked like it was opened?” If the answer is, “Not good,” you should consider tackling those workflows first. 

How is Twilio SendGrid preparing for MPP?

Since the initial announcement in June 2021, Twilio SendGrid has been working hard to understand how this development will impact our senders. We have also been working to determine what products or features we can deliver to help you navigate what could be a tumultuous time. 

Twilio SendGrid is taking a data-driven approach.

We have been building internal tools to monitor and compare the change in open rate prior to and after the release.

With this tooling in place, we will effectively monitor the impact of the release as adoption increases. When we have reliable details on the actual impact, we will share as much of it as possible with our senders to build a body of knowledge on how MPP adoption is changing the most basic signals associated with sending email.

Moreover, since the announcement in June, we have been putting our unparalleled data set to work to better understand what “non-human” engagement looks like and how we can identify it. 

Your email experts

While there is still quite a bit of uncertainty as to how exactly the MPP update will impact email senders, Twilio SendGrid’s team of email experts is working to provide you with the latest information: talking with fellow industry experts, analyzing initial data, and providing you the latest information (like this blog article). As more information becomes available, we will update you on the impact of MPP as well as provide best practices on how to handle the change.

If you are concerned about how the MPP feature will affect your email program, contact our expert services team for guidance. With over 130 years of combined experience, our experts team can help you set up your email program, solve deliverability issues, and provide ongoing assistance.



Luke is an email expert with a passion for solving difficult problems. Luke works on Twilio SendGrid’s Email Deliverability Operations team, monitoring and optimizing deliverability for all senders on the SendGrid platform. Luke has a deep understanding of SMTP, IP address and domain reputation systems, spam filters, blocklists, feedback loops, and email marketing best practices. If email is broken, Luke wants to help fix it.