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How will Apple’s iOS 15 Mail Privacy Protection impact email marketing?

How will Apple’s iOS 15 Mail Privacy Protection impact email marketing?

Apple released the iOS 15 update on September 20, 2021, with a new opt-in privacy feature called Mail Privacy Protection (MPP).

Its main purpose is to limit the ability of email senders and third parties to track if iOS Mail users have opened an email. Users can opt-in to mail privacy protection that hides their IP addresses, location, device type and open timestamp. The end-user experience will remain the same other than being given the option to “Protect their mailbox”.

This will affect the data you receive from email sends to HCPs and consumers from iOS devices.


This is a substantial shift in email marketing and such methods of tracking will become the new normal. These iOS 15 updates specifically impact the ability to track opens and open-rate email metrics, which can no longer be guaranteed on third-party platforms. With marketers no longer having visibility into open rate metrics among iOS 15 users who opted into this privacy protection, it will impact guarantees and investment protection.


Email marketing continues to be a valuable channel to deliver expanded information and education to physicians and consumers alike. Underscore’s approach to email marketing follows several tenets and will be as follows:

  • Currently, the Apple update affects approximately 35-45% of partner databases using iOS 15, which means open rates will continue to be tracked for 55-65% of email users.
  • Total delivery of sends will continue to be guaranteed, normally between 95-100%.
  • To continue to receive NPI-level data from partners to track sends and clicks.
  • Utilize historical data as a benchmark and apply it forward until actual results are available.
  • Prioritize partners who can provide alternative measurement solutions (e.g., read rates, click rates).

While open rates cannot be guaranteed, historical open rates prior to iOS 15 can be utilized to project program reach. Echo sends will continue to be deployed when a partner can definitively determine the set of users who did not open.

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