When iOS 15 rolled out on September 20, Email marketers started slooowly losing access to accurate open rates.
The once-reliable stat is getting distorted by a new iOS 15 feature: proxy opens.
Proxied opens, explained
When you email someone who uses Apple Mail on iOS 15, and has opted into Mail Privacy Protection (MPP), Apple downloads the email to a proxy server.
That reads as an open to many ESPs, though the user may not have opened the email.
As of October 13, more than 10% of emails opened via Apple Mail for iPhone were opened via proxy.
And Apple Mail for iPhone has cornered about 38% of the email market — so [scribbles furiously on napkin] 3% or more of email opens these days might be fake.
So far, just 30% of iPhone users have updated to iOS 15, and not everyone is opting in to MPP, so impact has been subtle.
But it’s poised to grow. Just yesterday, MPP became available to desktop Apple Mail users who upgrade to macOS Monterey.