Should you track email opens at all?
Open tracking is far less reliable than it used to be. Apple Mail Privacy Protection preloads tracking pixels for a large share of opens, whether or not the email was read. Reply rate is the steadier signal now.
The short answer
- Apple Mail Privacy Protection preloads images, including invisible tracking pixels, in emails read through Apple Mail. That registers an 'open' whether or not the recipient opened the message. Apple Mail accounts for a large share of all email opens.
- This makes a specific open rate percentage far less trustworthy as a precise metric than before Apple introduced the feature. A meaningful share of recorded opens reflect automated preloading, not genuine attention.
- Reply rate has become the more reliable signal for judging cold email performance. A reply requires genuine engagement in a way an inflated open count does not.
- Tracking pixels carry a second cost beyond inaccuracy. Some spam filters and deliverability systems weigh their presence negatively, and some recipients view them unfavourably on privacy grounds.
Why open rate stopped being a trustworthy number
Open tracking works by embedding a tiny, invisible image (a tracking pixel) in an email. When the recipient's email client loads that image, it registers as an open. That worked reasonably well as a directional signal for years. Then Apple introduced Mail Privacy Protection. The feature preloads all images in an email, including tracking pixels, whether or not the recipient ever opens or reads the message. Emails read through Apple Mail can register as opened the moment they arrive, whether or not a human ever looked at them.
Apple Mail carries a large share of email traffic. So industry benchmark reporting in 2026 puts commonly cited open rate figures anywhere from roughly 27.7% to 44%, depending on the data source and how heavily Apple Mail Privacy Protection is factored in. That range is wide enough to reflect measurement noise as much as real engagement differences. A specific open rate percentage no longer reflects genuine recipient attention the way it once did, across campaigns or across time.
Open tracking versus reply rate as a performance signal
| Metric | Reliability in 2026 | Why |
|---|---|---|
| Open rate | Low, inflated by Apple Mail Privacy Protection | Tracking pixels preload automatically regardless of genuine opens |
| Reply rate | High | Requires genuine engagement; cannot be automatically inflated the same way |
| Click rate | Moderate | More reliable than opens but still affected by some automated link scanning |
| Bounce and complaint rate | High | These are server-level events, not dependent on client-side image loading |
What to actually track instead
Shift primary attention to reply rate as the main signal of whether a cold email campaign is working. It requires a genuine human action that automated pixel preloading cannot fake. Open rate can still be kept as a rough, directional data point at large scale. It is useful for spotting a dramatic shift, not for fine-grained A/B comparisons. It should not be the metric a subject line test or a campaign decision is made on.
Disclosure: SalesCrew is our product. It shows reply rate and bounce/complaint data as the primary cadence performance signals. Open tracking is available, presented with the understanding that Apple Mail Privacy Protection affects its accuracy for a large share of recipients. It does not correct for Apple's pixel preloading. That limitation is inherent to open tracking as a mechanism, not specific to any one tool.
Do not A/B test subject lines using open rate alone
Questions
- What is Apple Mail Privacy Protection, and why does it break open tracking?
- It is a feature that preloads images, including invisible tracking pixels, in emails read through Apple Mail. It does this whether or not the recipient opened or read the message. That registers an 'open' event even for emails never seen, inflating open rate data for any recipient on Apple Mail.
- Should open tracking be removed from a cold email program entirely?
- Not necessarily removed, but downgraded as a decision-making metric. Open data can still give a rough directional signal at large scale. Treating a specific open rate percentage as a precise, trustworthy number is no longer accurate. Too much of it is automated pixel preloading rather than genuine opens.
- Does open tracking have any downside beyond inaccuracy?
- Tracking pixels are a known signal some spam filters and deliverability systems weigh negatively. Some recipients and platforms also view them unfavourably from a privacy standpoint, separate from the accuracy problem.