Why are my email open rates so high since 2021?

Apple Mail Privacy Protection pre-loads the tracking pixel for Apple Mail users, recording opens that did not happen. It inflates open rates and makes them unreliable.

Is open rate still useful?

As a rough deliverability tripwire and noisy relative signal, yes; as an absolute measure of engagement, no. Use clicks, conversions, and revenue per recipient instead.

What replaces open rate?

Click rate, click-to-open rate, and downstream conversion or revenue per recipient — behaviours a privacy proxy cannot fake.

Growth Marketing Glossary

Email open rate

email open ratenoun

Once email's headline metric, now a number you cannot fully trust.

Schematic — email open rate

Measures: delivered emails opened
Tracked by: a tiny invisible pixel
Inflated since: Apple MPP, 2021
Better signal: click and conversion

Forms & parts of speech

open rate · noun

Opens ÷ delivered emails.

"Open rate jumped after iOS 15 — Apple was opening the pixel, not the readers."

How opens are counted and why they broke

Open tracking works by loading a tiny invisible image when the email is viewed. If the image loads, the open is recorded. That mechanism is the metric's whole foundation — and its weakness.

Apple Mail Privacy Protection, launched with iOS 15 in 2021, pre-loads that image for Apple Mail users whether or not they open the message. Those machine opens inflate the rate and make it unreliable as an engagement signal.

What to use instead

Open rate still has uses — sudden drops can flag deliverability problems, and relative comparisons within Apple-heavy lists are noisy but not useless. As an absolute engagement number, it is no longer trustworthy.

Shift the scoreboard downstream: click rate, click-to-open, conversions, and revenue per recipient measure real behaviour. Build segmentation and automation on clicks and purchases, not on opens that a privacy proxy may have faked.

Worked example. Say a campaign to a list with many Apple Mail users reports a 55% open rate — far above the brand's history. The lift is not readers; it is Mail Privacy Protection pre-loading the tracking pixel for those subscribers. The honest read comes from clicks and revenue per recipient, which did not move.

Anchoring the campaign verdict on the inflated open rate would have declared a flat send a hit.

Failure modes to watch. Treating post-2021 open rates as real engagement; building re-engagement segments on opens that may be machine-generated; and comparing open rates before and after iOS 15 as if the metric meant the same thing.

Benchmarks

Open-rate benchmarks published after iOS 15 are distorted by machine opens. Treat them with caution and lead with click and revenue metrics.

Post-2021

inflated by MPP

Trust instead

clicks and revenue

Still flags

sudden deliverability drops

Ranges are illustrative; every published figure is cited from a named public source or labelled “RGM analysis.”

Synonyms & antonyms

Synonyms

open rateemail opens

Antonyms

unopened rate

Usage trends

Search interest for this term over the last five years:

View interest-over-time on Google Trends →

Common questions

Why are my email open rates so high since 2021?: Apple Mail Privacy Protection pre-loads the tracking pixel for Apple Mail users, recording opens that did not happen. It inflates open rates and makes them unreliable.
Is open rate still useful?: As a rough deliverability tripwire and noisy relative signal, yes; as an absolute measure of engagement, no. Use clicks, conversions, and revenue per recipient instead.
What replaces open rate?: Click rate, click-to-open rate, and downstream conversion or revenue per recipient — behaviours a privacy proxy cannot fake.

Related tools & calculators

Resources & people to follow

referenceApple — Mail Privacy Protection overview
referenceKlaviyo — email benchmarks

Curated, non-competitor resources verified per term.

Sources

trendsGoogle Trends — "email open rate"