How accurate is email client market share data when Apple Mail intentionally opens messages?

Summary

Apple's Mail Privacy Protection (MPP) significantly impacts the accuracy of email client market share data by inflating open rates due to automatic image loading. This makes open rates an unreliable metric for gauging genuine user engagement, especially within Apple Mail. Experts and marketers advise shifting focus to metrics like click-through rates, website traffic, and conversions. Additionally, A/B testing based on open rates is now less dependable. Regulations like GDPR and PECR add complexity by requiring consent for tracking pixels. Using third-party email apps introduces additional filters to consider.

Key findings

  • Inflated Open Rates: Apple's MPP inflates open rates, making them less reliable.
  • Inaccurate Market Share Data: Email client market share measurements based on image downloads are inaccurate.
  • Unreliable Engagement Metric: Open rates are no longer a reliable metric for measuring genuine user engagement on Apple Mail.
  • A/B Testing Issues: A/B testing relying on open rates is now less dependable.

Key considerations

  • Shift Focus: Focus on metrics like click-through rates, website traffic, and conversions for accurate performance assessment.
  • Re-evaluate Strategies: Re-evaluate email marketing strategies to account for distorted open rates.
  • Ensure Compliance: Ensure compliance with regulations like GDPR and PECR regarding email tracking and consent.
  • Filter Management: Consider the impact of third-party email app filters in addition to mailbox provider filters.

What email marketers say
9Marketer opinions

The accuracy of email client market share data has been significantly impacted by Apple's Mail Privacy Protection (MPP). Apple's MPP inflates open rates by pre-loading emails via proxy servers, making open rates an unreliable metric for gauging genuine user engagement, particularly among Apple Mail users. Consequently, relying solely on open rates can be misleading. Marketers are advised to shift focus towards more reliable engagement metrics like click-through rates, website traffic, and conversions to assess campaign performance accurately. A/B testing based on open rates has also become less dependable. Apple Mail filters add to existing spam filters if enabled. It is difficult to ascertain if open events from Apple Mail users are real, or which app was used.

Key opinions

  • Inflated Open Rates: Apple's MPP inflates open rates by automatically opening emails, distorting market share data.
  • Unreliable Metric: Open rates are no longer a reliable metric for Apple Mail users due to MPP.
  • Shift in Focus: Marketers should shift focus to more reliable engagement metrics like click-through rates and conversions.
  • A/B Testing Impact: A/B testing based on open rates has become unreliable due to MPP.

Key considerations

  • Re-evaluate Metrics: Re-evaluate which metrics you are using to determine campaign success and shift focus from open rates to click-through rates, website traffic, and conversions.
  • Adjust A/B Testing: Adjust A/B testing strategies to rely on click-based metrics and other engagement signals instead of open rates.
  • Filter Considerations: Third party email apps add to existing spam filters if they are enabled.
  • Data Accuracy: Be aware that open events from Apple Mail users may not be real.
Marketer view

Email marketer from EmailToolTester shares that Apple's Mail Privacy Protection (MPP) inflates open rates because it pre-loads all emails, even if the user doesn't open them. This makes open rates an unreliable metric for Apple Mail users.

August 2023 - EmailToolTester
Marketer view

Email marketer from Litmus explains that Apple's MPP skews open rates by automatically opening emails through a proxy server, making it difficult to accurately measure genuine user engagement. They suggest focusing on other metrics like clicks and conversions.

July 2023 - Litmus
Marketer view

Email marketer from Email on Acid notes that Apple’s Mail Privacy Protection has made A/B testing based on open rates unreliable. They recommend marketers shift focus to click-based metrics and other engagement signals for A/B testing.

November 2021 - Email on Acid
Marketer view

Email marketer from Mailchimp explains that the introduction of Apple's Mail Privacy Protection (MPP) means open rates are less reliable. They suggest focusing on other engagement metrics such as click-through rates and conversions to measure campaign success. They suggest exploring new ways to personalize emails to reach users.

October 2021 - Mailchimp
Marketer view

Email marketer from SuperOffice explains that Apple's Mail Privacy Protection can make open rates a vanity metric. They recommend that marketers place less importance on open rates and more on metrics that show real engagement like website clicks and goal conversions.

July 2021 - SuperOffice
Marketer view

Marketer from Email Geeks agrees with Marcel Becker's assessment that a large percentage of opens come from Apple devices due to Apple intentionally opening messages with their automations.

August 2023 - Email Geeks
Marketer view

Email marketer from Campaign Monitor shares that Apple’s MPP has changed email marketing and open rates are not as reliable. They suggest focusing on metrics such as click-through rates, website traffic, and conversions to gauge success.

February 2023 - Campaign Monitor
Marketer view

Marketer from Email Geeks explains that email client market share measurements using image downloads are inaccurate. Additionally, 3rd party email apps with their own spam filters will add to mailbox provider filters if enabled. Only Apple Mail for MacOS offers client side filters, not iOS. Also, open events from Apple Mail users cannot be determined if true or not, as well as which application was actually used.

May 2024 - Email Geeks
Marketer view

Email marketer from Sendinblue discusses Apple's Mail Privacy Protection (MPP) and its significant impact on email marketing metrics. They highlight that MPP inflates open rates due to the automatic loading of images through a proxy server, making it difficult to accurately assess user engagement.

August 2023 - Sendinblue

What the experts say
2Expert opinions

Apple's Mail Privacy Protection (MPP) has distorted email open rates, rendering them less reliable for measuring engagement. Experts suggest re-evaluating email marketing strategies and focusing on click-through rates and conversion rates to gauge email performance accurately.

Key opinions

  • Distorted Open Rates: Apple's MPP significantly distorts email open rates.
  • Less Reliable: Open rates are less reliable for measuring email engagement due to Apple's MPP.
  • Inflated Open Rates: Apple's Mail Privacy Protection has resulted in inflated open rates.

Key considerations

  • Re-evaluate Strategies: Re-evaluate email marketing strategies in light of distorted open rates.
  • Focus on Other Metrics: Focus on click-through rates, conversion rates, and other metrics to assess email performance.
Expert view

Expert from Word to the Wise discusses that Apple's Mail Privacy Protection has resulted in inflated open rates, making it harder to accurately track user engagement. They suggest marketers should consider using click-through rates, conversion rates, and other metrics to assess email performance.

May 2024 - Word to the Wise
Expert view

Expert from SpamResource suggests that Apple's Mail Privacy Protection (MPP) has significantly distorted open rates, making them a less reliable metric for gauging email engagement and requiring marketers to re-evaluate their strategies.

November 2022 - SpamResource

What the documentation says
3Technical articles

Apple's Mail Privacy Protection (MPP) is designed to enhance user privacy by hiding IP addresses and preventing senders from knowing if an email has been opened. This impacts the accuracy of open rate tracking, and together with broader privacy concerns and regulations like GDPR and PECR, it poses challenges for email marketers who rely on tracking pixels and need to obtain consent for their use.

Key findings

  • Privacy Protection: Apple's MPP enhances user privacy by hiding IP addresses and open information.
  • Inaccurate Tracking: MPP impacts the accuracy of open rate tracking, making it less reliable.
  • Regulatory Challenges: GDPR and PECR require consent for tracking pixels, which is difficult with features like MPP.

Key considerations

  • Privacy Compliance: Ensure compliance with privacy regulations like GDPR and PECR regarding email tracking.
  • Alternative Metrics: Explore alternative metrics for measuring email engagement due to the limitations of open rate tracking.
  • Transparency: Be transparent with users about data collection practices and respect their privacy choices.
Technical article

Documentation from the UK Information Commissioner's Office discusses the implications of email tracking under GDPR and PECR, noting that obtaining consent for tracking pixels is essential, a challenge given privacy features like Apple's MPP.

December 2022 - ICO
Technical article

Documentation from Apple details that Mail Privacy Protection hides a user's IP address and prevents senders from knowing if an email has been opened. This feature is designed to enhance user privacy, but it impacts the accuracy of open rate tracking.

January 2025 - Apple
Technical article

Documentation from MDN Web Docs explains tracking pixels, including their use in emails, and highlights the increasing privacy concerns and measures taken by email clients like Apple Mail to limit their effectiveness.

November 2021 - MDN Web Docs