04 · THE POLISH

Subject lines, and what keeps it sounding like you

Six subject-line shapes that work, and the short list of habits that separate a human email from an obvious AI one.

About 6 minutes

A good email with a weak subject line does not get read. These are the six shapes that work for business email, and you can ask the AI for any of them by name.

Six subject lines that work

[Action] + [their name or business] — Following up — Ridgeline Plumbing. Best for follow-ups and proposals.
Quick question about [topic] — Quick question about your website. Best for first contact and check-ins.
Next steps for [project] — Next steps for your social setup. Best for onboarding and proposals.
[Timeframe] update on [topic] — [Month] update on your campaign. Best for reporting and check-ins.
Re: [their last subject line] — Re: Quote request — signage. Best for replies and follow-ups.
[Plain statement of fact] — Invoice 1042 — payment due. Best for invoices and admin.

The pattern across all six: they say what the email is about. No curiosity gaps, no "you won't believe", nothing that reads like marketing. Business email gets opened because the subject line is useful, not because it is clever.

What separates a human email from an obvious AI one

Keeps it yours

One specific detail that shows you know them
Under 150 words for most emails
One clear action at the end
Their name in the opening line
A tone you named in the prompt — warm, direct, firm but kind
Your normal sign-off, the one you always use

Gives it away

Sending the draft without reading it
Corporate filler — as per my last email, please be advised, I trust this finds you well
Three calls to action so they can 'choose'
Over-explaining, or apologising more than once
Em-dashes and phrasing you would never say out loud
Emotionally sensitive messages straight out of the tool

The thirty-second read

Before any AI-drafted email goes out, run it past these five. It takes half a minute and it catches almost everything.

The pre-send check

0 of 5

Everything in it is actually true — no invented dates, numbers or promises.
No [square brackets] left in the text.
There is one detail in it that only I would know.
There is exactly one thing I am asking them to do.
I would say this out loud, in these words.

The one thing to remember

One clear action per email. Three options is the fastest way to get no reply.

PreviousThe other four: welcome, decline, review request, overdue invoice

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