How to Write Email Subject Lines People Actually Open (40 Examples)

Simple rules for subject lines that get opened, plus 40 examples for sales, newsletters, events and announcements you can adapt today.

In short: Good subject lines are clear, specific and honest: they tell the reader what’s inside and why it matters to them, in the first 30–40 characters. Use the preview text, sound like a person, avoid shouting, and test two options on a slice of your list before sending to everyone.

Your subject line decides whether anything else in your email gets read. The good news: great subject lines follow a few simple rules, and you don't need to be a professional copywriter to use them.

The rules that matter most

Be clear before clever. People decide in a second. "20% off all winter coats this weekend" beats "Brrr-illiant news!".
Lead with the benefit. What does the reader get? Savings, a solution, an invitation, news they care about.
Keep it short. Many phones show around 30–40 characters. Put the important words first.
Use the preview text. The short line shown after the subject is free space — use it to add detail.
Sound like you. A friendly, human tone stands out in an inbox full of shouting.
Don't trick people. Misleading subject lines are against the law in the US (CAN-SPAM) and Canada (CASL), and they destroy trust.
Go easy on CAPITALS and symbols. "FREE!!! $
quot; looks like spam to people and filters alike.

Formulas that work

The clear offer: [Offer] + [deadline]
The question: a question your customer is already asking
The how-to: "How to [result] in [time]"
The news: "New: [thing]" or "Now open: [thing]"
The personal note: what a friend would write

40 examples you can adapt

Sales and offers

20% off everything until Sunday
Your member discount is inside
Last day: free shipping on all orders
The winter sale starts now
3 days only: buy one, get one half off
A thank-you gift for you (expires Friday)
Prices drop at midnight
Your cart is still waiting — and it's 10% off

Newsletters and tips

5 ways to keep your plants alive this winter
The one mistake we see every week
What we learned from 1,000 haircuts
Your monthly money checklist
This month's favourites (chosen by our team)
The quick fix for [common problem]
Read this before you [common task]
Everything new this month, in 2 minutes

Events and invitations

You're invited: tasting night on Thursday
Save your seat — 12 spots left
Doors open at 6 — see you there?
Join our free workshop next Tuesday
Members-only: early access starts tomorrow
Reminder: tomorrow at 7 pm

Announcements

We're open on Sundays now
New menu, same favourites
Introducing [product] — made for [customer]
Big news (and a small gift)
We moved! Here's our new address
Bookings for December are open

Personal and relationship

Happy birthday, [first name] — this one's on us
It's been a while, [first name]
Thanks for being with us for a year
A quick question for you
Did this help?
We'd love your opinion (1 minute)

Curiosity (use sparingly, always deliver)

The secret ingredient is out
We weren't sure about this one…
You asked, we listened
The most popular thing we've ever made
Before you buy a [product], read this
We almost didn't send this

Test, don't guess

Try two subject lines on a small part of your list, see which earns more opens and clicks, then send the winner to everyone else. Our A/B testing guide shows how.

Why some subject lines work and others don't

People scan their inbox in seconds, asking two silent questions: "Who is this from?" and "Is this worth my time right now?" Your sender name answers the first. Your subject line must answer the second.

That's why specific beats clever. "Our spring sale starts tomorrow — 20% off everything" answers the question instantly. "Spring has sprung!" makes the reader do the work — and most won't.

The preview text: your second subject line

The preview text (or preheader) is the grey line after the subject in most inboxes. If you don't set it, the inbox shows the first words of your email — often "View in browser" or "Having trouble reading this email?". Always write it yourself:

Subject: Your member discount is inside
Preview: 15% off everything until Sunday, plus free gift wrapping

Together they tell a complete story.

Personalisation that actually helps

Adding a first name can help, but relevance matters more:

Location: "Toronto: our pop-up is this Saturday"
Past purchases: "New colours of the jacket you love"
Behaviour: "Still thinking about the yoga starter pack?"

These need segments or tags, but they consistently beat generic subject lines.

How to test without fooling yourself

Write two genuinely different options (not one word changed).
Send each to 10–20% of your list.
Wait at least a few hours; judge by clicks, since opens are inflated by Apple Mail privacy features.
Send the winner to the rest.
Write down what you learned and look for patterns across several tests.

A quick self-check before you hit send

Can someone tell what's inside from the subject alone?
Is the most important word in the first 30 characters?
Would you open it if a stranger sent it?
Is it 100% honest about the content?

Let AI give you a head start

Stuck? Reepio's AI writer suggests subject lines in your brand voice from a one-line brief — and you choose, edit or test them. Try it free.

Frequently asked questions

How long should an email subject line be?

Short enough that the important words are visible on a phone — often around 30 to 50 characters. Put the key information first, and use the preview text to add detail.

Should I use emojis in subject lines?

One relevant emoji can help an email stand out, especially for consumer brands. Avoid using several, and test whether your audience responds better with or without.

Does adding the first name improve opens?

Sometimes. Personalisation can help when it feels natural, but it’s no longer novel. A specific, useful subject line usually matters more than the name — test it with your own list.

What words trigger spam filters?

Modern filters look mainly at your sender reputation and authentication, not single words. Still, avoid ALL CAPS, excessive punctuation and misleading phrases, which look spammy to people too.