Your open rate is lying to you (and AI just made it worse)

16 June 2026

AI has quietly started reading our email for us, summarising it before we've properly read it and sometimes before we've even opened it. For you, as someone sending email, that means the open rate in your reports is worth even less than it used to be. Here's what's going on, and what to watch instead.

I was going through my inbox the other day and noticed Gmail had started doing something new. I'd open an email and Google's AI had already boiled it down to a couple of lines at the top. One was a supplier's newsletter - I read the two-line summary, got what I needed, and never scrolled down or clicked a single link.

I'm on Gmail. If you're on an iPhone it's more aggressive again: Apple writes a summary that sits in your inbox before you've even opened the email. Either way, the machine is reading our email for us now and handing us the gist.

If you send email to customers, that's worth understanding, because it changes what your reports are actually telling you.

Opens were already a bit of a fib

Your open rate has been unreliable for years, and that part has nothing to do with AI.

Back in 2021 Apple switched on something called Mail Privacy Protection. When an email arrives in Apple Mail, Apple loads the invisible tracking pixel that tells us a message was "opened" - whether the person opened it or not. So a chunk of your list gets counted as having opened when plenty of them never looked.

This is Mailchimp's own position, and Mailchimp is the platform we send on. Their words: Apple Mail preloads the pixel "even if your contact hasn't opened the email, resulting in unreliable open metrics." Most lists have a fair few Apple Mail users on them, so your open rate has been padded for a while now.

AI has widened the gap

Opens were already soft. AI summaries stretch them further.

Apple's summaries sit in the inbox before anyone opens, in place of the preview line you used to write. People can now read what your email is about without opening it. For Apple Mail users that's the worst of both worlds: the pixel still fires, so they show up as "opened," even though all they actually saw was a one-line summary before moving on.

Gmail does it a bit differently. Its AI summary appears after you open, or when you ask for one, so it doesn't fudge the open rate. But people still lift the key point out of your email without clicking through to your site, and click-through rates have dipped since Google turned it on.

Either way you land in the same place. The number of people genuinely reading your email keeps drifting away from the number your report calls an "open."

What to look at instead

The useful part, and again this is straight from Mailchimp's own guidance.

Stop using opens as your scoreboard. Watch the things a person has to physically do - clicks, replies, people unsubscribing, and the actual enquiries or sales that follow a send. If you re-send to "people who didn't open," change it to "people who didn't click," or you'll be pestering people who read it perfectly well.

Opens still work as a rough trend line. If they fall off a cliff, something's broken and worth checking. But as proof your email landed, they're soft, and getting softer.

Can you see the summary before you send?

Not really, and I'd be a bit suspicious of anyone who says they can.

The summary gets written on each person's phone, the moment your email arrives, and it comes out slightly different for everyone. No tool shows you the exact version your customers will see. The closest you'll get is sending yourself a test and opening it on a recent iPhone.

What you can control is what the AI has to work with. It builds the summary from your subject line and the first couple of lines. So put the most important thing first. Don't bury it three paragraphs down under a big header image, or the AI will faithfully summarise the waffle and skip the bit that mattered.

Which is just good writing, when you think about it. Say the important thing first. You're only being rewarded for what a busy reader wanted from you anyway.

If keeping on top of all this for every send sounds like a job you don't have time for, that's the part we do. Hit Send is back, now part of Ark Advance, writing and sending newsletters for people who'd rather get on with running their business. If you'd like it off your plate, drop us a line.