How does Apple Mail Privacy Protection (MPP) affect the tracking of email opens and clicks, and how are machine opens categorized?

Key findings

• Inflated open rates: MPP preloads all email images and tracking pixels, leading to an automatic registration of an open regardless of whether the user actually interacts with the email. This artificially inflates open rate metrics, making them less indicative of true user engagement. For more details on this, see our article on how accurate email open rates are.
• Machine-generated opens: The opens recorded due to MPP are primarily server-side HTTP fetches (machine opens) rather than direct user actions. These opens frequently lack explicit device information (e.g., mobile or desktop) in the HTTP referer, making device categorization by tracking tools inaccurate.
• Limited impact on clicks: Unlike opens, clicks are generally still reliable metrics. They originate from the user's browser, not Apple's preloading proxy, and thus are not directly affected by MPP's image loading mechanism. However, other privacy-preserving features (like VPNs) could still mask some click data.
• Anonymized data: MPP hides users' IP addresses, which prevents senders from gathering data related to geolocation and device type from these preloaded opens. This anonymization impacts the depth of audience segmentation and personalization efforts based on open data.

Key considerations

• Adjusting open rate analysis: Marketers should re-evaluate the significance of open rates as a primary engagement metric. Instead of relying solely on opens, focus on other indicators of engagement that are less impacted by MPP, such as clicks, conversions, and website activity. Learn how to accurately measure email open rates without relying on image pixels.
• Categorization of machine opens: Email service providers and analytics platforms should ideally categorize MPP opens separately, rather than mislabeling them as real mobile or desktop opens. This provides a clearer picture of genuine user engagement versus automated activity.
• Focus on click-through rates: Clicks remain a more reliable indicator of active engagement post-MPP. Marketers should optimize campaigns for compelling calls-to-action to encourage clicks, providing a more accurate measure of interest. For more, see how to increase email click through rate.
• Understanding proxy behavior: While Apple's MPP primarily affects opens, other email providers like Gmail also use image proxies that can impact tracking. Understanding how these proxies work can help identify artificial email opens and clicks and filter them out.
• Adapting engagement strategies: The shift in open rate reliability necessitates a broader view of subscriber engagement. Marketers should consider factors like overall subscriber activity, conversion rates, and the value of content consumed, moving beyond simple open rate metrics. You can learn more about the implications in this article on the impact of Apple's Mail Privacy Protection.

Key opinions

• Open rate skepticism: Many marketers now view open rates with significant skepticism, understanding that they no longer accurately reflect human interaction but rather automated image fetches by Apple's servers. This has led to a re-evaluation of how to measure email performance.
• Categorization challenges: There's a widespread recognition that attributing MPP opens to specific devices (mobile vs. desktop) is problematic, as the underlying data often doesn't distinguish between them. Marketers seek clearer categorization or a separate designation for these machine-generated opens.
• Click reliability: Most marketers believe that clicks remain a more dependable metric than opens. Clicks signify a deliberate action by the user, and unlike opens, are not routinely pre-fetched by privacy protection mechanisms (like MPP).
• Shift in focus: Many email marketers have shifted their focus to metrics further down the funnel, such as click-through rates, website visits, and conversions, to gauge true campaign effectiveness rather than relying heavily on open rates. This is vital for understanding how internet service providers track email engagement.

Key considerations

• Adapting A/B testing: A/B tests that traditionally used open rates as a success metric (e.g., subject line testing) now need to pivot towards other engagement indicators, like click-through rates, to determine winning variations. This is crucial for improving email campaign performance and why your emails might be failing.
• Rethinking segmentation: Marketers who segmented lists or triggered automations based on open behavior must now find alternative engagement signals for these processes, such as click activity or purchase history, to maintain personalization and relevance.
• Holistic engagement view: It's essential to develop a more comprehensive understanding of engagement that combines email metrics with website behavior and customer journey data. This provides a fuller picture of how subscribers interact with brands. Read about the impact of the MPP on email marketing.
• Communication with clients/stakeholders: Marketers need to educate clients and internal stakeholders about the changes in open rate data, managing expectations and ensuring that performance is evaluated using appropriate, reliable metrics.

Key opinions

• Server-side fetches: Experts consistently highlight that MPP opens are merely HTTP fetches from Apple's servers, not actual user interactions from a device. This distinction is crucial for understanding why these opens are not accurate indicators of engagement.
• Inaccurate device categorization: Tools attempting to categorize MPP opens as 'mobile' or 'desktop' are fundamentally incorrect, as the data provided by Apple's proxy often lacks the necessary information for such distinctions. These are machine-generated, not device-specific. This relates to how to identify artificial email opens.
• Clicks are different: Clicks operate differently from image requests and are not routed through the same image proxies. This makes them generally more reliable for identifying actual user engagement and device interaction.
• Other privacy features: While MPP doesn't directly impact clicks, experts note that other privacy features, such as VPNs or browser-level proxies, can still mask user data for clicks, introducing a level of uncertainty.

Key considerations

• Tool-dependent categorization: The way MPP opens are counted and reported heavily depends on the specific email marketing platform or analytics tool being used. Experts recommend scrutinizing how these tools categorize such activity. Read more on how email analytics platforms classify client usage.
• Shifting metrics: Experts advise a strategic shift away from over-reliance on open rates. Instead, focus should be on more actionable metrics like click-through rates, conversions, and direct website engagement to accurately assess campaign performance.
• Understanding privacy features: It is important to understand the technical workings of Apple's privacy features, including how they handle IP addresses and image requests. This helps explain the discrepancy in open rates and supports adapting strategies accordingly. See our guide on how iOS 15 affects email marketing privacy.
• Adapting IP warmup strategy: Given the impact on open rates, experts also discuss how MPP might affect traditional IP warmup strategies that rely on consistent open engagement to build sender reputation, necessitating adjustments. Learn about Apple Mail Privacy's impact on IP warmup.
• Evolving analytics: The industry continues to evolve its analytics capabilities to provide more nuanced insights in a privacy-first world. Experts suggest staying informed about new methodologies and metrics that offer deeper understanding of subscriber behavior.

Key findings

• Pre-fetching mechanism: Documentation confirms that MPP functions by pre-fetching all email content, including tracking pixels, when an email is delivered to an Apple Mail inbox. This action is registered as an open, regardless of actual user engagement.
• Anonymized user data: MPP hides users' IP addresses, which means senders cannot determine geographic location or precise device information from these preloaded opens. This is a key privacy enhancement.
• Impact on specific metrics: Official sources explicitly state that metrics like total opens, unique opens, and open rates are directly impacted and inflated by MPP. Other metrics like clicks are generally not affected by the same mechanism. More information can be found on Mailchimp's documentation about Apple MPP.
• Limited effect on clicks: Documentation clarifies that MPP does not interfere with the tracking of clicks within an email. Clicks are handled separately as they involve interaction that redirects to a web browser, not merely image loading.

Key considerations

• Adjusting data interpretation: Documentation encourages email senders to adapt their data analysis by recognizing that open rates no longer solely indicate user engagement. This requires a shift towards other reliable metrics. You can also review why your email deliverability rate is wrong.
• Implication for A/B testing: Documentation implies that A/B tests relying on open rates, such as subject line tests, will need to evolve their methodology to use alternative engagement indicators for valid results.
• Understanding 'machine opens': It is critical for email systems to clearly categorize these 'machine opens' to differentiate them from actual human interaction, providing more transparent reporting for senders. For similar scenarios, consider why automated scripts are opening your emails.
• Privacy by design: MPP reflects a broader industry trend towards privacy by design. Marketers should consider this in their overall strategy, building trust by respecting user data privacy rather than circumventing it.