Every email we send now gets read twice — once by software, then maybe by a person. Apple Mail writes its own summary of a message and shows it in place of the sender’s preview text, before the open. Gmail summarizes on open. Both extract the concrete things — names, dates, numbers, offers — and flatten everything vague into filler. For a publishing company that lives and dies by email, that changed our job description this month.

What the machine rewards

The summarizers are surprisingly consistent about what survives them. A specific fact in the first sentence survives. A date survives. A number survives. Atmosphere does not survive, and neither does a clever slow build — the summary simply skips to whatever concrete payload it can find, and if there isn’t one, the summary makes the email sound like nothing.

That has an uncomfortable implication: the writer no longer fully controls the first impression. The subject line is still yours. The first sentence is effectively shared custody.

What we changed in our pipeline

We run our email through a review queue: drafts land in a database, a person approves them on a dashboard, and a dispatcher ships exactly what was approved, byte for byte. This month that pipeline picked up three new rules.

First, every email must carry a preheader — one factual sentence that completes the subject line rather than repeating it. Our dashboard refuses to let an email be approved without one, and the dispatcher refuses to send one that slips through. We wrote the rule knowing Apple may replace the preheader with its own summary; the discipline is the point, because the same sentence has to be able to do its job in either world.

Second, the first sentence of every email now has to be a standalone factual summary of the whole message. If the machine builds its precis from our opening, we want the opening built for that reader.

Third, subject lines state the concrete fact up front, inside the roughly forty characters a phone shows. We checked this against our own history before adopting it: our best-performing subjects were already the plainly specific ones, and the curiosity-bait experiments sat at the bottom of the table. The machines and the readers, it turns out, agree.

What we’d tell you to steal

Write the preheader before the body. It’s the fastest way to find out whether an email actually says anything — if you can’t produce one factual sentence about it, the email isn’t ready.

Then reread your last few sends and ask what an extraction engine would pull from each. If the honest answer is “nothing concrete,” the fix isn’t better prose. It’s deciding what the email is for, and saying that thing first.