• by Ray Schultz , Columnist, October 4, 2021

As expected, the open rate is no longer a reliable metric for emails sent to Apple Mail users, thanks to Apple’s Mail Privacy Protection.  

That doesn’t mean brands should stop sending email — quite the contrary, judging by a new study by Movable Ink. 

One of the new features for iOS15 users is the prefetching of content for users of the Apple Mail client. “There has been active conversation within the email marketing industry with little data available to inform the discussion,” writes Movable Ink Michael Nutt in a blog post.  

Movable Ink studied emails opened from September 20 -- the iOS 15 GA release date -- to October 3 for all of its clients, amounting to over 45 billion content impressions.  

In addition, the firm analyzed Apple Mail with Mail Privacy Protection enabled (iOS 15) vs iOS 14 across every day in that same time period.

The result? It found that 80% of Apple Mail users get content rendered less than a minute prior to open.

In contrast, 5% see content that is one to four minutes old. And 5% apiece see content that is:

• 5 to 34 minutes old 
• 35 to 179 minutes old
• Over 179 minutes old.  

But Apple Mail is only one part of the picture: 89% of all recipients see content less than a minute old. Also 2.6% apiece see content that is: 

• 1 to 4 minutes old 
• 5 to 34 minutes old
• 35 to 179 minutes old
• Over 179 minutes old. 

Why is this important?

“With MPP enabled and sometimes prefetching content on a user's behalf, “it is not possible to directly determine whether an open event was prefetched by the iOS 15 mail client or the result of direct user interaction,” Nutt writes. 

But he continues that by “looking at the duration between each user's 'open' event and 'click' event it's possible to infer which type of open it was.

Nutt adds that users with iOS 14 and iOS 15 devices behave similarly.“Prior to the iOS 15 release date, users could only obtain iOS 15 by enrolling in the beta program,” he notes. 

“Following the release, iOS 15 traffic has increased by an order of magnitude from 30M impressions/day to over 1.2B impressions/day which indicates that the iOS 15 traffic represents real users,” Nutt continues."

Vivek Sharma, co-founder and CEO of Movable Ink, says that, after analyzing "over 45 billion content impressions since the MPP went into GA, we drew two main conclusions."

"Firstly, we found that, as predicted, opens are no longer a reliable metric for Apple Mail users," Sharma says. "Savvy marketers have been preparing for this shift for the last three months and already started shifting their scorecards to more meaningful down funnel metrics such as clicks, conversions and revenue."

"Secondly, and more surprisingly, we discovered that caching is occurring far closer to real-time than anticipated," Sharma continues. "This research should be welcome news to marketers who have use cases that rely on fast-changing data to inform personalized experiences.

Sharma concludes, "The Main Privacy Protection update is another push for marketers to use zero-party and first-party data assets and activate them into personalized content at scale. Movable Ink believes all marketers should easily be able to deliver millions of unique, relevant experiences to all people, across all channels, on their marketing lists. Even with the increased push towards data privacy, the future of personalization is bright.”