How does Apple Mail Privacy Protection (MPP) inflate open rates?
Still have a question, spotted an error, or have a better explanation or a source we should cite?
Apple Mail's Mail Privacy Protection works by fetching email images through Apple's own servers, on behalf of the user. The key detail: this happens shortly after delivery, not when the user actually opens the email.
Your tracking pixel is an image. Apple's servers request it. Your ESP logs a request from Apple's IP address and records an open. From your analytics system's perspective, this looks identical to a real human opening the email. There's no reliable way to distinguish a proxy prefetch from a genuine open.
The inflation happens because Apple prefetches for MPP-enabled users regardless of whether they open the email. A message can sit unread in someone's inbox, get prefetched by Apple, and appear as an open in your analytics. That user may delete the email without ever seeing it. Your open rate still goes up.
The scale of this effect depends on your audience's Apple Mail usage. For newsletters aimed at consumers or Apple-heavy professional audiences, it's substantial. Many senders saw their open rates jump 20-30 percentage points immediately after MPP launched in September 2021, with no corresponding change in actual engagement metrics like click rates or conversions.
Most ESPs now report MPP-influenced opens separately. If yours does, pay more attention to the non-MPP open rate and to click data. The clicks still require a human to actually tap a link, so they remain a more reliable signal of real engagement. Here's a deeper look at what that means for your analytics overall.
Contributors
Who worked on this answer
Every name links to their profile. Every company links to their site. Real people, real accountability.
