Impact of iOS 15 Update On Open Tracking

Apple announced Mail Privacy Protection for their Mail app on iOS 15, iPadOS 15, and macOS Monterey devices. According to Apple, Mail Privacy Protection stops senders from using invisible pixels to collect information about the user. It prevents senders from knowing when they open an email, and masks their IP address so it can't be linked to other online activity or used to determine their location.

When a user selects "Protect Mail Activity," Apple pre-loads images in the email even for messages that have not been opened. This means almost all emails sent to recipients using the Mail app may have obfuscated results showing false opens. Testing has confirmed that Apple's proxy servers pre-fetch images regardless of whether the recipient actually views the message, making it impossible to distinguish real opens from machine-generated ones.

The mail service doesn't matter — it's the endpoint where the email is opened that's important. If an email is opened on the Mail app on iOS 15, iPadOS 15, or macOS Monterey devices, it will have the option to not be tracked via the user privacy selection.

It's not the operating system alone allowing for this tracking. It's only when the user has iOS 15 AND checks their mail via the native Apple Mail app. If the user is on Gmail or another mail app that is not Apple Mail, even if on iOS 15, the privacy controls will not be in effect. This is a critical distinction: the privacy protection is tied to Apple's Mail client, not to iOS as a platform.

Open tracking will be significantly affected. Since Apple pre-fetches all images, nearly all emails opened in Apple Mail clients with MPP enabled will report as opened — regardless of whether the recipient actually viewed the message. Open rates will inflate substantially and become unreliable for Apple Mail users.

Click tracking, however, appears largely unaffected. Testing has determined that Apple does not modify the query string or change the user agent string for link clicks. First-party click tracking will continue to work as expected. When configuring Private Relay (part of iCloud+), users can choose to have an anonymous IP address that preserves their approximate location, or one in a broader region — but the click data itself remains accurate.

The key metrics affected include: open-based segmentation, send-time optimization models trained on opens, open-time personalization and live content (weather widgets, countdown timers, device-specific app store badges), and subject line A/B testing that relies on open rates.

As the world's largest email sender delivering 40% of the world's commercial and transactional email, Bird has a comprehensive view of the email landscape. In the 2021 Benchmark Report, 38.1% of all opens and clicks came from Apple Mail app clients — 25.7% on iPhone, 9.6% on desktop, and 2.8% on iPad. This makes Apple Mail the second largest client family after Gmail.

With the release of iOS 14.5, when US-based users were prompted to authorize tracking by an app, 96% opted out. Given this precedent, adoption of Mail Privacy Protection is expected to be extremely broad. The industry has also seen the demise of third-party cookies in advertising and Apple's IDFA tracking restrictions on the App Store. It was inevitable that Apple would extend privacy protections to email open tracking.

The implications for email marketing are significant across multiple workflows:

List hygiene and segmentation strategies that relied on opens as an engagement signal need to shift to clicks, site activity, and conversions. Without access to reliable opens, senders must rely on deeper behavioral signals to determine if a real human is still engaged.

Subject line testing that relies on open tracking will be flawed for Apple Mail users. Metrics like clicks and conversions further down the funnel will need to be used instead.

Send-time optimization will also be affected because it often takes opens into account to determine the right time to send based on engagement patterns.

Open-time personalization and live content will be broken. Weather widgets, store locators, device-specific app store badges, and countdown timers that draw from context at the time of open are all at risk due to Apple's image caching behavior.

Monitoring inbox placement becomes even more critical because assuming emails landed in the inbox based on opens will no longer be reliable.

Bird's Inbox Tracker and Competitive Tracker products don't use open pixels to track opens, so those continue to work as they always have. On the sending side, Bird has added a field to both Webhooks and the Events API to indicate when an open has been pre-fetched.

These pre-fetched opens are still included in reporting since they serve as a valuable signal that an email address is valid — specifically, they indicate the address is linked to a powered-on Apple device, almost certainly associated with a real human. The new flag makes it easy to distinguish these machine-generated opens from actual engagement events.

Bird continues to innovate its solutions to provide email professionals with better insight into the true performance of their email programs, shifting focus from open-based metrics to click-based engagement, conversion tracking, and multi-channel behavioral signals.