Email Open Rates Are Not the Point

Every marketing team has a number it reports without thinking, and in email that number is the open rate. It is easy to explain, it moves when you change the subject line, and it makes a bad month look survivable. It is also, since 2021, one of the least trustworthy figures on the whole report.

The reason is a privacy feature. Apple's Mail Privacy Protection, which shipped with iOS 15 in September 2021, pre-loads the images in a message before the user opens it. Tracking pixels are images. So an open can be recorded for a message nobody read, and the email analytics firm Litmus has put Apple's mail apps at around half of all tracked opens.

The effect was not subtle. Open rates rose across the industry in the months after the change, and plenty of teams celebrated. Others quietly rebuilt their reports. If half your audience is counted as opening everything, an average open rate stops describing readers at all; it describes device settings. The subject-line test you ran last week measured almost nothing.

Meanwhile the number that really decides your programme moved somewhere else. From February 2024, Gmail and Yahoo required bulk senders — broadly, anyone sending more than 5,000 messages a day — to authenticate their mail with SPF, DKIM and DMARC, to offer one-click unsubscribe, and to keep reported spam complaints below 0.3 percent. Cross that line and your mail stops arriving.

Three complaints in a thousand is a strict ceiling, and it changes the incentives. Mailing an old list to hit a monthly number is no longer a harmless habit; it is a risk to every message the company sends, including the ones people asked for. A password reset that lands in spam costs far more than a campaign nobody opened.

So what should replace the open rate? Three numbers survive the change. Clicks, because a click needs a hand. Replies, if you actually ask for them. And the outcome you wanted in the first place: trials started, orders placed, meetings booked, counted per thousand messages delivered rather than per thousand sent. Unsubscribes belong on the same page, not in an appendix.

None of this makes email weaker. It makes it honest. A list that people read is worth more than a list that is merely large, and the new rules push everyone towards the first kind. Report the open rate if your boss asks for it. Just do not let that one figure decide what you send next week.