Subject lines that lift open rates

Your subject line is the highest-leverage sentence you'll write all issue. You'll spend an hour on the body and thirty seconds on the subject, and the thirty-second bit decides whether the hour was wasted. That maths should bother you more than it currently does.

Internal subject lines have one advantage and one disadvantage over marketing email. Advantage: people know you. You're not a stranger fighting spam filters; you're a colleague with a name. Disadvantage: you're competing with work email — messages from their manager, their clients, the finance system chasing a timesheet. Work email always feels more urgent, because it usually is.

So you can't win on urgency, and you shouldn't try. You win on clarity: telling people, in about eight words, exactly why this issue is worth four minutes of their day. Here's how.

Specific over clever

This is the rule that governs everything else. "3 changes to expenses from Monday" beats "Big news inside!" every single time, and it isn't close.

Marketing email uses curiosity gaps because strangers have nothing to lose by ignoring them. Your colleagues are different: they will open a vague subject once, discover it was "please clear the fridge", and quietly downgrade you. Curiosity gaps annoy colleagues, and colleagues don't have to forgive you — they just stop opening. You're playing a repeated game, and vagueness loses repeated games.

Compare:

❌ You won't want to miss this one
❌ Exciting updates from the People Team!
❌ October Newsletter

✅ Parental leave is changing — here's the two-minute version
✅ The office move: dates, desks, and what to bin
✅ Benefits window closes Friday (it takes 3 minutes)

The good ones tell you what's inside and roughly what it'll cost you to read. That honesty is the whole strategy.

Lead with the most-cared-about item

Your subject line is a table of contents of one. Each issue has, say, six items — but the subject only fits one, so pick the item the most people will care about, not the one leadership most wants pushed.

These are often not the same thing. Leadership wants the strategy refresh at the top; your readers want to know whether parking is changing. Put parking in the subject line. The strategy refresh gets read anyway, because they opened.

A quick test: if you stood up at all-hands and could announce only one thing from this issue, which one would make people look up from their laptops? That's your subject line.

Name names

"Why Priya's team shipped the new portal early" pulls more opens than "Engineering update." People are wired to care about people, and in a company of 20–250 you know most of them. Use that.

✅ Meet Amara, Josh and Wei — this month's new faces
✅ How Dan's team cut onboarding from 3 weeks to 4 days
✅ Sofia's last week (and what she wants you to know)

Names also do a second job: colleagues forward issues to the people named in them, which is distribution you didn't have to earn.

Number it

A consistent issue marker — "The Loop #14", "The Roundup, Issue 22" — builds a habit. People learn the sender and the shape, and a numbered series signals this is a thing that reliably exists, not a one-off broadcast. It also quietly tells new joiners there's a back catalogue.

The number alone isn't enough, though. "The Loop #14" with nothing else is a label, not a reason to open. Which brings us to the formula.

A repeatable formula

When you're staring at the subject field at minute 46 of your production routine, don't invent from scratch. Use this:

[Issue marker] — [most-cared-about item], plus [teaser of 1 other]

"The Loop #14 — new parental leave policy, plus who won the hackathon"

It works because each part does a distinct job: the marker builds the habit, the main item earns this week's open, and the teaser rewards the people who'd have skipped the main item. Three hooks in one line, no cleverness required.

More examples with the formula doing the lifting:

✅ The Roundup #8 — pay review dates confirmed, plus the new desk booking app
✅ Issue 31 — we're hiring 12 people, plus Thursday's lunch is on us
✅ The Loop #19 — what the engagement survey said, plus a dog in the office

That last teaser is doing exactly what a teaser should: being small, human and true.

What kills opens

A few habits reliably drag open rates down. Avoid all of them:

• The word "Newsletter" in the subject. It signals skippable. "October Newsletter" is an instruction to archive. Say what's in it instead.
• Every subject sounding identical. "Weekly update — 3 Oct", "Weekly update — 10 Oct"... you've trained readers that nothing changes, so nothing needs opening. Keep the marker consistent and vary everything after the dash.
• Sender confusion. The best subject line dies next to a sender called "noreply". Send from a real, consistent name — that whole battle (from name and preview text) gets its own lesson next.
• Overpromising. "HUGE announcement" for a stationery cupboard reorganisation costs you the next three opens. The subject is a promise; the body has to keep it.
• Burying the noun. Phones show roughly the first 40 characters. "An important update regarding changes to our parking policy" clips before the point; "Parking changes from 1 September" leads with it.

Write three, pick the most specific

Never send your first draft subject line. The routine that works: write three options, ask "which one is most specific?", send that one. Not the funniest, not the one you're proudest of — the most specific. Nine times in ten the specific one wins, and the tenth time it draws.

If you're blank, don't sit there suffering. There's a swipe file of 50 subject lines in the hub, grouped by job — digest, policy change, recognition, urgent ask — built for exactly this moment. And the app's AI drafts will propose subject lines from your issue content, which makes a decent first option to beat with your other two.

This week

Open your last three sent issues and rewrite each subject line using the formula: issue marker, most-cared-about item, plus one teaser. Compare your rewrites to what you actually sent. If the rewrites are obviously better — they will be — pin the formula somewhere you'll see it on production day, and never send a first-draft subject again.