How do Apple MPP and privacy tools skew cold metrics?

Apple Mail Privacy Protection (MPP), introduced in 2021, fundamentally changed email tracking reliability.

How MPP works:

Apple Mail pre-fetches all email content including tracking pixels

This triggers open events even when recipients haven't actually opened

IP addresses are masked through proxy servers

Opens appear for every Apple Mail user with MPP enabled

Impact on cold email metrics:

Open rates: Inflated by 30% to 50% or more for Apple Mail recipients

Location data: Proxy IPs make geographic targeting unreliable

Time of open: Pre-fetch timing doesn't reflect actual reading

Other privacy tools:

Hey.com and other clients block tracking by default

Browser extensions block tracking pixels

Corporate email gateways may strip tracking elements

Practical response:

Treat open rates as directional, not accurate

Focus on reply rates as the reliable engagement metric

Consider disabling open tracking entirely

Segment reporting by email client if possible

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