Email senders have come to rely on the value of rich tracking available when communicating via email, especially recipient open tracking. Senders then use open data to optimize their customer experiences. For example, personalizing with branching automations, changing sending patterns with thoughtful sunset policies, and measuring the engagement and ultimately the success of campaigns and notifications.

Now, however, the reliability of open tracking is at risk. The launch of Apple’s Mail Privacy Protection (MPP) and increased adoption over the last 3 weeks has caused the email industry as a whole to experience inflation in anonymous open activity.

MPP prompts Apple Mail application users on the newest operating system to enhance their security by anonymizing their open engagement activity.

As a result, senders, regardless of their email service provider, are seeing an increase in random open events, without the ability to tell what is triggered by Apple machines vs. what is actual human engagement for MPP-enabled users. 

Don’t fret, however. After significant research, testing, and monitoring, Twilio SendGrid can consistently identify this anonymous open data with our Apple Open Indicator—now available from the SendGrid Event Webhook. The Apple Open Indicator is a boolean field, “sg_machine_open,” included with all open events to identify MPP-enabled user opens. When the “sg_machine_open” boolean field is “true,” it will indicate that the open came from a user with MPP enabled. It was either triggered randomly from an Apple machine or opened by the MPP-enabled recipient in Apple Mail but returned anonymous data.

With the Apple Open Indicator, Twilio SendGrid empowers senders to identify anonymous data in order to parse it from conventional engagement data. This gives senders the power to respect recipient privacy and adapt email sending strategies to rely less on open data for MPP-enabled users while continuing to harness the power of conventional email engagement data when available. 

For more recommendations for how to adapt to Apple’s Mail Privacy Protection, see our comprehensive guide, join our webinar on Email Metrics in the Era of Mail Privacy Protection, and consider personalized guidance from our team of email experts.



As a Senior Product Marketing Manager at SendGrid, Lindsey works cross-functionally to bring new products and features to market. Acting as the voice of the customer, Lindsey works with our engineering, product, marketing, sales, and support teams to ensure that customer needs are met and that SendGrid continues to deliver on our promise of enabling customers to send with confidence.