The Best Email Subject Lines: 87 High Open-Rate Subject Lines

BONUS MATERIAL: Free Email Subject Line Worksheet

So you’ve started to send emails to your newly built (and growing) email list

The problem? It’s becoming more difficult to come up with emails your list will actually open and read. 

Even worse, when you do figure out what to say, your open rates aren’t anywhere near where you wish they’d be. If this sounds familiar, you’re not alone. 

In fact, coming up with the best email subject line to get your email actually read is a common problem, especially when emails are being sent to your subscribers by everyone and their moms.

And it’s not hard to see why everyone is investing in email marketing:

  • 92% of online adults use email (for context...only 62% of online adults use Facebook)[*][*]
  • Email marketing has an ROI of 3800%[*]
  • The average value of a sale from an email is at least 3x higher than social media[*]

So how can you stand out and write email subject lines people will actually open? 

87 Of The Best Email Subject Line Examples 

To help you find the perfect email subject line for every email you send, we’ve broken this guide down into a few handy sections based on the types of emails you might be creating

Use the links below to jump to the most relevant section for you…

Email subject line categories 

  1. Sumo’s Best Email Subject Lines
  2. Content Promotion Email Subject Lines
  3. Sales Email Subject Lines
  4. Cold Email Subject Lines
  5. Follow Up Email Subject Lines
  6. Transactional Email Subject Lines

P.S. I’ll also share 3 bonus insider tips to help you improve your email subject lines. Keep reading to learn all you need to know about killer subject lines. 

Sumo’s Best Email Subject Lines

After sending billions of emails to our customers and subscribers at Sumo, here are 10 of the best performing email subject lines we’ve uncovered: 

Subject Line
Open Rate
1. I was right - and that’s not good for you
2. 13 email marketing trends you must know
3. Before you write another blog post, read this
4. Are we still on for 12?
5. You don’t want FOMO do you?
6. We’re starting in 5 HOURS
7. Missed you, how’s Thursday?
8. How 35 influencers grew their sites from 0-10K visitors
9. It’s time to rethink Black Friday
10. How to Google-proof your mobile site in 2017

These subject lines are the best of the best. But you’re going to need more than 10 killer subject lines to take your email marketing to the next level.

Below, I’ll share 77 more incredible email subject line formulas to help you crush your email marketing targets. 

Content Promotion Email Subject Lines

You’ve spent hours crafting an EPIC piece of content, now you want people to read it. 

And one of the best ways to drive traffic directly to your latest piece of content is your mailing list. 

For example, at Buffer, our mailing list is the #1 referrer to our new content on the day we launch it:

Screenshot of mailing list referrer stats

So if you’re not using your mailing list to promote your new content, you’re missing out on a ton of traffic. 

Here are 23 subject line formulas you can use in your content promotion emails

1. The New Email Subject Line

If the majority of your emails are promoting your latest blog posts, this little trick from GrooveHQ could be just want you’re looking for. 

As you can see, their email subject lines are pretty straight-forward:

GrooveHQ email subjects example

However, look at how they use the word “new” to make opening their emails even more desirable.

2. The Lessons Email Subject Line

  • Formula: [Number] Lessons [I/We] Learned by [Action You Took]
  • Example: 21 Lessons I Learned by Exercising Every Morning

Tim ferriss interesting email subject example

3. The How They Done It Email Subject Line

This formula lead to one of Sumo’s best-performing emails with an open rate of 57%

4. The Best Of Email Subject Line

5. The You vs. The World Email Subject Line

Here’s an example of a similar subject line from Runkeeper:

Where do you rank email subject example

6. The Here’s Why We Email Subject Line

Sumo used this exact headline and received an INCREDIBLE 46% open rate when we announced our name change from SumoMe to

7. The Big Mistake Email Subject Line

8. The Authority Email Subject Line

Here’s The Authority Email in action: 

Tony Robbins email subject example

9. The Results Email Subject Line

Check out this headline being used by Drift below: 

Leadbot email subject example

10. The Urgency Email Subject Line

  • Example: Open this right now
  • Formula: [Action] Now 

Check out a variation of this email from the UFC below: 

UFC email subject example

11. The Case Study Email Subject Line 

Case Study email subject example

12. The How To Email Subject Line

Sumo 1000 subscribers email subject example

13. The School Of Email Formula Subject Line

14. The Do This Email Subject Line

15. The Branded Newsletter Email Subject Line

  • Example: The Traffic & Conversion Newsletter #24
  • Formula: [Name of Newsletter] [Issue #] 

16. The Roundup Email Subject Line

17. The Avoid Email Subject Line

You can see this subject line in action from Houzz: 

Houzz avoid email subject example

18. The Three-Point Email Subject Line

  • Example: UFC, sore thumbs, and power words
  • Formula: [Topic 1], [Topic 2], and [Main Topic] 

This formula is used by Tim Ferriss when he’s promoting his latest podcast episodes and blog posts: 

Tim Ferriss email subject example

19. The Art Of Email Subject Line

Hiten Shah used this subject line for his Product Habits email: 

Producthabits email subject example

20. The % Rule Email Subject Line

21. The Most Interesting Email Subject Line

Here’s an example from Tim Ferriss:

Most interesting tim ferriss email subject example

22. The Can’t Believe Email Subject Line

23. The Normally Email Subject Line

Sales Email Subject Lines

Email marketing has a return of 44.25x

If someone is on your mailing list, there’s a very good chance they’re interested in what you’re selling. 

But turning your subscribers into paying customers is a tough trick for any marketing to master. 

And before anyone parts with their hard earned money, you first have to have a subject line worthy of opening...

Here are 17 subject line formulas you can use in your sales emails

24. The Last Call Email Subject Line

  • Example: Last call: SEO That Works closes in 3 hours
  • Formula: Last call: [Name Of Product] closes in [#] hours 

Blinkist use a variation of this formula to offer discounts to users on their mailing list: 

Blinkist email subject example

25. The Problem Solver Email Subject Line

If your product directly solves a problem for your audience (which it should), use this formula to grab their attention and entice them to open the email. 

Here’s an example of this subject line from Onnit: 

ONNIT email subject example

26. The Try Out Email Email Subject Line

British burger restaurant Byron Burger used a variation of this subject line to promote one of their new recipes: 

Byron Burger Club email subject example

27. The Flash Sale Email Email Subject Line

  • Example: Flash Sale: Ogilvy on Advertising 50% Off
  • Formula: [Flash Sale] [Name of Product] [Discount] 

Tribe used this subject line to promote a recent sale: 

TRIBE email subject example

28. The Limited Time Sale Email Subject Line

  • Example: 48 hours left: 1 year of Beacon Unlimited for free
  • Formula: [Time Left]: [What’s on offer] for [Discount]

Scarcity can boost open rates (and sales) massively. If there’s a time limit on the offer you’re emailing about or limited availability, tell your reader directly in the subject line. 

We used the example headline above to promote our Beacon partnership and it resulted in a 53% open rate.  

29. The Quick Announcement Email Subject Line

  • Example: Quick announcement: The marathon running guide is here
    Formula: Quick Announcement: [Topic] is here

foundr email subject example

30. The Call Out Email Subject Line

  • Example: SaaS owners! Here’s how to reduce your churn rate
  • Formula: [Audience] [Topic] 

Use this email subject line to speak directly to your audience and show them exactly how your product will benefit them. 

31. The Social Proof Email Subject Line

  • Example: Proof that 30 days to shredded works
  • Formula: Proof That [Product] Works 

32. The Don’t Buy This Email Subject Line

  • Example: Don’t buy NBA 2K18 until you read this
  • Formula: Don’t buy [Product Name] until you read this 

33. The Versus Email Subject Line

  • Example: Fake businesses vs real businesses
  • Formula: [Subject] vs [Subject] 

34. The Death Of Email Subject Line

  • Example: The death of blogging
  • Formula: The Death Of [Topic] 

35. The Question Email Subject Line

Brain Dean quite often uses questions in his killer email subject lines: 

Brian Dean email subject example

36. The “You” Email Subject Line

  • Example: You, a best selling author?
  • Formula: You, A [Desired Result]? 

37. The Imagine Email Subject Line

Here’s an example of this subject line from the NRDC:

Imagine America email subject example

38. The Seasonal Discount Email Subject Line

  • Example: Save 25% on shoes this spring!
  • Formula: Save [Discount] [Items] This [Season]! 

Last call email subject example

39. The ‘You’re Not Doing’ Subject Line

  • Example: The most surprising Sumo features you aren’t using
  • Formula: The Most Surprising [Product] features you aren’t using

40. The Can’t Be Wrong Email Subject Line

  • Example: 5,000 people can’t be wrong
  • Formula: [Number] People Can’t Be Wrong 

41. The Use This Email Subject Line

  • Example: Use this workout plan
  • Formula: Use This [Thing] 

Cold Email Subject Lines

If you’re running a business, you’ll have to send cold email. That’s just a fact.

For example, you might:

  • Reach out to prospects to pitch your business
  • Want to interview well-known influencers for your blog
  • Meet industry VIPs and learn from the best

No matter what you’re trying to achieve, and how great your finely tuned email copy may be, you’ll fail if the recipient doesn’t open your email. 

Here are 16 formulas you can use for cold email subject lines: 

42. The Found You Through Subject Line

  • Example: I Found You Through Mark Zuckerberg
  • Formula: I Found You Through [Contact First Name] [Contact Last Name]

When LeadGenius tested various cold email subject lines, they found this one generated an AMAZING 86.6% open rate.

43. The Better Way Email Subject Line

  • Example: A better way to save on insurance
  • Formula: A better way to [achieve goal]

Here’s an example of the Better Way subject line:

Bteam webinar email subject example

44. The Real Reason Email Subject Line

  • Example: The real reason marketers use Sumo
  • Formula: The Real Reason [Target Market] [Attracted To Product/Topic] 

45. The Truth Email Subject Line

  • Example: The truth about buying lawnmowers
  • Formula: The Truth About [Topic/Person]

    Onnit used this headline formula in a recent campaign: 

ONNIT truth email subject example

46. The Problem Email Subject Line

  • Example: The problem with cheap running shoes
  • Formula: The Problem With [Insert Problem] 

47. The Specific Event Email Subject Line

  • Example: SumoCon 2020 Tickets
  • Formula: [Event Name] [Reason for Messaging]

Kyle Gawley used this formula to get a 50% open rate and 29% response rate on his cold emails[*]

48. The Let Me… Email Subject Line

  • Example: Let me save you 20% on heating bills
  • Example: Let me [action]

49. The Right Person Email Subject Line

  • Example: Are you the correct contact?
  • Formula: [Ask who you should speak to]

50. The Can I Help Email Subject Line

  • Example: Can I help increase your conversion rate?
  • Formula: Can I Help with [Topic/Problem]?

51. The Idea Email Subject Line

52. The Content Share Email Subject Line

  • Example: Ash, just wanted to share this video with you
  • Formula: [Name], just wanted to share this [content] with you

53. The Goal Email Subject Line

  • Example: Your sales goal
  • Formula: Your [goal/target]

Nutmeg email subject example

54. The Found You on Email Subject Line

  • Example: Found you on Twitter
  • Formula: Found you on [network/website]

55. The Helper Email Subject Line

  • Example: Calorie counting got you down? Can I help?
  • Formula: [Topic] got you [emotion]? Can I help?

56. The Greeting Email Subject Line

  • Example: Afternoon, Ash
  • Formula: [Time of day], [Name]

57. The Chat Email Subject Line

  • Example: Dave, I’d love to chat about weight training 
  • Formula: [Name], I’d love to chat about [topic]

Follow Up Email Subject Lines

Whether you’re emailing someone you just met or trying to get a response from a cold call email, following up is incredibly important. 

80% of sales require an average of five follow ups, and what’s even more mind blowing is that 44% of salespeople give up after one attempt[*][*]

If you’re not following up, you’re missing out on huge opportunities to grow your business. 

Here are 13 formulas you can use for follow up email subject lines: 

58. The We Discussed Email Subject Line

  • Example: Here’s the quote we discussed
  • Formula: Here’s the [topic] we discussed

59. The Thanks for Your Time Email Subject Line

  • Example: Chris, thanks for your time today
  • Formula: [Name], thanks for your time [today, yesterday, last week]

60. The Still On Email Subject Line

  • Example: We still on for Tuesday?
  • Formula: We still on for [Date/Time]?

Here’s a super smart variation of this email from Virgin Atlantic to follow up flight searches:

"Still thinking?" reminder email subject example

61. The Ways to Get Started Email Subject Line

  • Example: 5 Ways to Kill Your Next Workout With Sumo Protein 
  • Formula: [X] Options to [Experience Growth] with [Product]

62. The I Forgot Email Subject Line

  • Example: I forgot to mention
  • Formula: [Provocative statement]

63. The We Haven’t Email Subject Line

  • Example: We haven’t stopped brainstorming ideas
  • Formula: [We haven’t] [Action]

64. The Missed You Email Subject Line

  • Example: Missed you, how’s Thursday?
  • Formula: Missed you, [how’s day]?

65. The To-The-Point Question Email Subject Line

  • Example: Next step?
  • Formula: [Short question]

Justin Jackson used this subject line in a message to his email list: 

To-the-point email subject example

66. The ‘re’ Email Email Subject Line

  • Example: Follow Up re: Nutrition Advice
  • Formula: Follow Up re: [Topic discussed]

67. The Awesome to Meet You Email Subject Line

  • Example: Awesome to Meet You at SumoCon Last Week
  • Formula: Awesome to Meet You at [Event/Place] [Date/Time]

68. The Touching Base Email Subject Line

  • Example: Touching Base Regarding Our Pitch Yesterday
  • Formula: Touching Base Regarding [Topic] [Date/Time]

69. The Quick Check In Email Subject Line

  • Example: Checking in on our estimate
  • Formula: Checking in on [topic]

70. The Steve Jobs Email Subject Line

  • Example: One more thing about our meeting
  • Formula: [One more thing] about [topic]

Transactional Email Subject Lines 

Chances are your company sends a ton of transactional emails. 

Things like:

  • Welcome emails
  • Receipts
  • Billing reminders 

As these emails are usually triggered by customer actions, like making a purchase or signing up to your product, transactional emails have an open rate 8x higher than normal emails[*]

But you still want to do everything in your power to ensure your transactional emails are opened. After all, they often contain super important information. 

Here are 7 formulas to help you craft amazing transactional email subject lines. 

71. The Welcome Email Subject Line

  • Example: Welcome to Sumo!
  • Formula: Welcome to [Brand/Name]! 

Here’s an example welcome email: 

Wealthify email subject example

72. The Let’s Get Started Email Subject Line

  • Example: Welcome to Warby Parker! Try on some glasses now
  • Formula: Welcome to [Brand/Name] - [Action encouraged]

73. The Thank You Email Subject Line

  • Example: Dollar Shave Club: Thank you for being a customer
  • Formula: [Business name]: Thank you for being a customer

Check out an example thank you email from Medium below: 

Medium thank you email subject example

74. The Reminder Email Subject Line

  • Example: Last Wednesday You Added Nike Running Shoes to your basket
  • Formula: [Date/Time] You [Action took]

75. The Order Email Subject Line

  • Example: Your order of Spiderman 3
  • Formula: Your order of [product name]

76. The Next Steps Email Subject Line

  • Example: Welcome to Uber - here’s how to take your first ride
  • Formula: Welcome to [product name] - [next steps]

77. The Action Required Email Subject Line

  • Example: Action Required: Confirm Your Email Address
  • Formula: Action Required: [Task]

Action required email subject example

3 Bonus Tips To Improve Your Email Subject Lines

The above email subject line examples and formulas will no doubt help you to improve your open rates.

But to truly maximize the potential of your emails, you’ll need to do a little experimenting and testing with your subject lines. 

Here are three ways to further improve your open rates. 

1. Experiment with emojis

A report from Experian found that 56% of brands using emojis in their email subject lines saw a higher open rate on their emails[*].

You could could try out a few of the formulas listed above with added emojis. For example:

  • Welcome to Sumo! ?
  • The problem with cheap running shoes ?
  • The best marketing guides of 2020 ❤️

The below chart from Mailchimp shows the most popular emojis used in subject lines[*]

Graph of most popular emojis used in subject lines

2. Test various lengths

For most businesses, there’s no link between subject line length and open rates[*]

But you should think about where your subscribers are opening their email.

In 2017 and beyond, it’s likely that the majority of your opens will come on mobile - around 66% of all email in the U.S. is now opened on smartphones or tablets[*]

With smaller screens, you need to ensure your subject line fits within the allocated space. To help out, Campaign Monitor put together this handy chart showing the number of characters displayed on various mobile devices[*]

Table that shows number of characters displayed on different email clients

To ensure your subject line appears correctly in every browser and device, try to keep it to between 30-60 characters. 

3. Use one time sensitive words

Using time sensitive words like “urgent” and “important” can result in much higher open rates[*]

Time sensitivity open rate graph

Where applicable, try to weave these words into some of your subject line formulas to inspire action from your subscribers. 

For example: 

  • Important: 21 Lessons I Learned by Exercising Every Morning
  • Sale Alert: 20% Off Sumo Pro
  • Breaking: Warren Buffet’s investing secret

We all know the story of the boy who cried wolf and because not every email you send will need immediate action from the reader, it can be best to use this tip sparingly.

This means that when you do include time sensitive words in your subject line, your readers know they MUST act. 

Benchmarking Your Email Open Rates

Many factors affect the average open rates, including how your subscribers became subscribers in the first place and if you’re sending an email to an extremely segmented part of your list. 

But according to Mailchimp (reported on by SmartInsights) after analyzing hundreds of millions of emails, they’ve found that the average email open rate is anywhere between 15% and 25% depending on the industry:

Different industries email open rates

Now, you don’t need to take these numbers as gospel. 

Yours can be lower depending on your situation, but if you can stay in the 15%-25% range, you can be confident that you’re doing well. 

Skyrocket Your Open Rates With Irresistible Email Subject Lines 

You now have some of the most highly-coveted email subject lines at your disposal. 

In this post, I revealed to you why email subject lines matter, what makes a good email subject line, and even gave you all of the best email subject line templates.

All there’s left to do now is to actually go use these subject line templates. So just scroll up, pick your favorite subject line formula, and start taking action. 

Get The Free Email Subject Line Worksheet


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