Email Subject Lines: 150+ Examples Sorted by the Job They Do

Plenty of subject lines fail for a dull reason: they don't say what's in the email.

A good email subject line tells the reader what's inside and why it matters to them, in plain words, short enough to read on a phone. Put the important words first, make the line match the email, and pair it with preview text that adds something new. Below are 152 original email subject line examples, grouped by the email they belong to.

Each one comes with its character count (spaces and punctuation included) and a short note on why it works. After the examples: how long a subject line should be, what actually gets email filtered, how to write preview text, and how to test two lines against each other instead of guessing.

What makes a good email subject line?

A good subject line does one job: it gets the right person to open the right email. That sounds obvious, but it rules out most of the tricks. A catchy line that tricks people into opening gets an open and loses trust. A line that tells them what's inside may get fewer opens from people who don't care, and in our experience more clicks from the ones who do.

Five habits cover most of it:

1. Say what's inside. "Your quote, as promised" beats "Quick question" because the reader knows what they'll get.

2. Be specific. Numbers, names, dates and products give the eye something to hold on to: "Invite a teammate (it takes 30 seconds)".

3. Front-load the words that matter. Phones show far less of a subject line than desktops (more on length below), so the first few words carry the line.

4. Sound like a person. Write the subject the way you'd write it to one customer. Sentence case helps here; see our page on subject line capitalization.

5. Match the email. In the US, the CAN-SPAM Act requires that the subject line "accurately reflect the content of the message" (FTC). It's also just good manners.

The good email subject lines below follow those five habits. Swap in your own product, numbers and dates; a line that's true for someone else's business is filler in yours.

These are the subject lines that work for welcome emails.

A new subscriber has just told you they want to hear from you. The welcome subject line should confirm they're in the right place and deliver what they signed up for.

These are the subject lines that get onboarding emails opened.

Onboarding emails work when each one points at a single next step. Name the step, and if it's quick, say how quick.

These subject lines sell without sounding like spam.

The plainest sale subject lines tend to be the clearest: the offer, the deadline, and nothing pretending to be something else. For a longer list sorted by type of sale, see promotional email subject lines.

Scarcity and urgency only work once if they're fake. Use "63 are left" or "ends tonight" only when it's true.

These subject lines keep newsletters from going stale.

A newsletter subject line has to earn the open every issue. Lead with the most interesting thing in the issue, not the issue number alone.

If you're rethinking the newsletter itself, our newsletter templates cover layout.

See it in Spreeflo: send a newsletter as a Broadcast and turn on Resend to people who didn't open, which goes out after a wait you choose with its own subject line. It's a built-in second chance to try a different line on the people the first one missed. Click around the live tour →

These subject lines win back people who stopped opening.

A win-back email asks one question: do you still want these? Make it easy to say yes, and honest about what happens if they don't.

These follow-up email subject lines get answered.

A follow up email subject line should point back to something real: a request, a call, a quote. For the full emails, see our sales follow-up email templates; for deal-stage emails, sales email subject lines.

For work emails to clients and partners (meeting requests, proposals, invoices), there's a separate list of business email subject lines.

These subject lines announce product updates people read.

Say what changed and who it affects. If action is needed, say so in the subject, and keep "Action needed" for emails that genuinely need it.

These subject lines get feedback and reviews.

Feedback requests get answered when they say how small the ask is and tie it to something the customer just did.

How long should an email subject line be?

Short enough that the important part survives on a phone. The published guidance agrees on the direction, if not the exact number:

So write for the phone first. Put the words that carry the meaning in roughly the first 30 characters, and treat 40 to 60 as the outer edge. The 152 lines on this page run from 19 to 50 characters, with a median of 36; 123 of them are 40 characters or fewer, and none is longer than 9 words.

Length isn't the goal in itself. "Last day for 20% off" (20 characters) is short because the email is simple. A proposal follow-up can run longer if every word earns its place.

What gets a subject line sent to spam?

No single word sends an email to spam. Filters add up many signals, and mailbox providers care most about whether people want your email.

• Spam filters score, they don't ban. SpamAssassin, the open-source filter, adds points per rule and treats a message as spam at 5 points by default. Its rule for a subject written entirely in capitals adds 0.5 (SpamAssassin rules). One signal rarely decides it; several together can.

• Complaints matter more than words. Google asks senders to keep the spam rate reported in Postmaster Tools below 0.3%, and recommends staying below 0.1% (Google). Yahoo also sets 0.3% (Yahoo). A misleading subject line is a fast way to earn complaints.

• Some patterns look like spam. Litmus warns that all caps and exclamation points are often associated with spam emails and can harm your sender reputation, and it advises getting your purpose across without spam words (Litmus).

• Fake replies are out. Google's guidelines say not to start a subject with "Re:" or "Fwd:" unless the message really is a reply or forward (Google).

In our view, the word "free" in an offer people asked for is fine. "FREE!!! Act now" to a list that never opens is not.

Should email subject lines use emojis?

One, if it adds meaning, and never in place of the words. Litmus suggests one or two at most, chosen to convey the email's main message, and notes that not every email client supports emoji, so keep a text fallback (Litmus). Email Tool Tester adds that emoji display varies across devices and clients, and that one emoji usually counts as two characters (Email Tool Tester). None of the 152 examples here uses one, which is deliberate: each should work in plain text first. If you add an emoji, test the line with and without it.

Pair every subject line with preview text.

Preview text is the line of copy the inbox shows after the subject. Use it to add the second half of the message, not to repeat the first. Litmus recommends keeping preview text under 90 characters (Litmus).

Set it every time. Leave it empty and the inbox may show whatever text comes first in your email, such as a "View in browser" link.

Here is how to test a subject line instead of guessing.

Send two versions to two random halves of the same audience, then compare clicks, not opens. Three rules keep the test honest:

1. Change only the subject line. Same email, same send time, same audience.

2. Judge on clicks (or replies, or revenue). Apple's Mail Privacy Protection downloads remote content in the background by default, whether or not the reader engages with the message (Apple). The tracking pixel that records an open is remote content, so open rates include emails nobody read.

3. Get enough people in each version. Small differences need big samples to mean anything.

Here's an illustrative example of the third rule. Version A gets a 6.6% click rate and version B gets 5.2%. With 2,000 people in each version, that's 132 clicks against 104, and a standard two-sided, two-proportion z-test gives p ≈ 0.06: the difference could still be chance. With 4,000 people in each version and the same rates (264 against 208 clicks), p ≈ 0.008, and you can be fairly confident A is better. If your list is small, test bigger differences (a question against a statement, a number against no number) rather than one word.

In Spreeflo, a subject line test is a Random Split step in a campaign or journey: set the slider to 50%, add a Send Email step on each path with a different subject, and compare the two emails in the report, where every number (opened, clicked, replied, attributed revenue) filters to the contacts behind it. Random Split and A/B testing are on the Starter plan.

Then personalise. Spreeflo renders Liquid in subject lines and preview text, so {{ contact.first_name | default: "there" }} puts a name in the line with a safe fallback. AI variables go further: on the Professional plan, a variable you define in the template, like {{ ai.subject_hook }}, is written for each recipient at send time from your prompt, using facts such as their recent site activity and purchases. They run on your own OpenAI key, so you pay OpenAI directly for what you use, with no AI markup from Spreeflo; during the free trial they work with no key. Our guide to AI variables shows how to write the prompt and preview the output, and Random Split is how you check the personalised line beats the plain one.

The broader point

A subject line is a promise about the email underneath it. Write one that tells the truth in a few specific words, send it to the people it's actually for, and let a test decide between your two best ideas. In our experience, that beats any list of power words.

Build this in Spreeflo

Spreeflo lets founder-led teams test subject lines with Random Split, personalise them with Liquid, and see which version brought in revenue, from $16 a month on Starter. Per-recipient AI variables are on Professional, from $24 a month, with the AI writing billed by OpenAI to your own key. It's 2 to 3x more affordable than Mailchimp.

Try the journey builder, no login → · See pricing

Common questions

What is a subject line in an email?

It's the line of text the inbox shows for an email before anyone opens it, followed by the preview text. It works as the email's title: it tells the reader what's inside and why to open it now. Phones show only about 25 to 30 characters of it, Litmus reports, and in the US, CAN-SPAM requires it to reflect the content of the message.

What makes a good email subject line?

It tells the reader what's in the email and why it matters to them, in specific, plain words. It puts the key words first so they survive on a phone, matches the content of the email, and works with the preview text instead of repeating it.

How long should an email subject line be?

Litmus recommends no more than 9 words and around 60 characters, and reports that phones show about 25 to 30 characters, so put the important words first and treat 40 to 60 as the limit.

Should email subject lines use emojis?

Use one at most, and only when it adds meaning. Litmus suggests one or two at most and notes that not every email client supports emoji. Make sure the line still makes sense without it, and test it.

What words trigger spam filters in subject lines?

No single word does. Filters like SpamAssassin add up many signals, and mailbox providers weigh spam complaints heavily. Litmus warns that all caps, exclamation points and spam words can harm your sender reputation, so avoid stacking them, and never mislead.

How do you A/B test subject lines?

Split one audience randomly into two groups, send each the same email with a different subject, and compare click rate rather than open rate, since Apple Mail Privacy Protection loads emails in the background. Use a few thousand people per version if you're testing a small change.

Read these next

• Business email subject lines: 80 examples for every kind of work email

• Sales email subject lines: 60 that get demos booked

• Promotional email subject lines: 70 for launches, discounts and last chances

• Should email subject lines be capitalized?

• Email Marketing Bible, chapter 7: Words that work

Sources

• Litmus: Email subject line best practices, read 28 October 2026

• Litmus: The ultimate guide to preview text support, read 27 October 2026

• Email Tool Tester: Email subject lines character limits, read 28 October 2026

• Google: Email sender guidelines, read 27 October 2026

• Yahoo Sender Hub: Best practices, read 27 October 2026

• FTC: CAN-SPAM Act compliance guide for business, read 27 October 2026

• Apache SpamAssassin default rule scores and default preferences, read 27 October 2026

• Apple: Mail Privacy Protection & Privacy, read 27 October 2026