For years, the open rate was the first number anyone looked at after a send. It was simple, instant and easy to compare. Today, for many lists, it is mostly fiction.
What changed
Apple’s Mail Privacy Protection (MPP), introduced in 2021, preloads email content, including the invisible pixel used to track opens, through Apple’s servers. That happens whether or not the person ever reads the email (Litmus).
Apple is also the largest source of tracked opens. Litmus’s email client market share data has shown Apple accounting for around half of all tracked opens (Litmus). If a large share of your audience uses Apple Mail with MPP switched on, a large share of your “opens” never happened.
What that breaks
- Open rate as a success metric. It trends upward regardless of quality.
- Subject line tests judged on opens. The winner may simply be the version sent to more Apple users.
- Automations triggered by opens. “If opened, send follow-up A” now fires for people who never read the first email.
- Engagement-based list cleaning. Inactive subscribers can look active, so they stay on the list and quietly hurt deliverability.
- Send-time optimisation based on open times.
The metrics that still mean something
Clicks and click-through rate
Clicks require a real person to act. Click-through rate (clicks divided by delivered emails) is now the most reliable engagement signal for most campaigns.
Conversions and revenue per email
What happened after the click: sign-ups, demo requests, purchases, revenue. This is the number the business actually cares about.
Replies
For sales-style emails and ABM outreach, a reply is the strongest signal of all.
Unsubscribes and complaints
These tell you when relevance or frequency is off. Google asks senders to keep spam rates under 0.1% and never reach 0.3% (Google).
List health
Growth, bounce rates and the share of subscribers who have clicked in the last few months. A list can grow while its genuinely engaged core shrinks.
Practical changes to make
- Report on clicks and conversions first. Keep opens as a rough directional signal at most, clearly labelled.
- Rebuild open-based automations to trigger on clicks, site visits, form fills or other real actions.
- Judge subject line tests on clicks or downstream conversions.
- Redefine “active subscriber” using clicks and site activity, not opens.
- Segment by client where possible, so you can compare engagement for Apple and non-Apple audiences.
Where AI helps
Email reporting now needs more context: several metrics, several segments, trends over time. AI is useful for:
- summarising each campaign’s results in plain English, highlighting what changed;
- spotting segments where clicks are falling even though opens look stable;
- suggesting hypotheses for the next test;
- building a consistent monthly report so trends are easy to see.
Always check the numbers behind any AI summary before it goes to a stakeholder.
The takeaway
Open rates are no longer a reliable measure of whether people read your emails. Shift your reporting and your automations to real actions such as clicks, conversions and replies, and you will get a much more honest picture of what your email programme achieves.
End-to-end reporting and analysis is part of our email marketing service. For the broader reporting approach, read campaign reporting with AI.
