Updated: 80 Best Email Subject Lines (With Formulas and Examples)

Bonus Material: Email Subject Line Formulas Worksheet

Want to improve your email open rates?

To help, we’ve put together a list of 80 professional subject line formulas with examples — categorized into the five most common emails we all send.

Can’t wait to test these email subject lines out? We got you covered with a worksheet with formulas you can pick from and fill out when you send your next email!

Get the Email Subject Line Formulas Worksheet Now

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
69%
2. 13 email marketing trends you must know
64%
3. Before you write another blog post, read this
61%
4. Are we still on for 12?
61%
5. You don’t want FOMO do you?
60%
6. We’re starting in 5 HOURS
59%
7. Missed you, how’s Thursday?
59%
8. How 35 influencers grew their sites from 0-10K visitors
57%
9. It’s time to rethink Black Friday
57%
10. How to Google-proof your mobile site in 2017
53%

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.

PART ONE: CONTENT PROMOTION EMAIL SUBJECT LINES

You’ve spent hours crafting an EPIC piece of content, now you want people to read it. One of the best ways to drive traffic directly to your latest piece of content is your mailing list.

For example, Sumo’s email list is the #1 referrer to their new content — driving over 22,000 visits per month.

Best Email Subject Lines: Screenshot of graph showing the number of monthly sessions on Sumo

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

Groove HQ uses this little trick well to make opening emails about their latest blog posts more desirable:

Best Email Subject Lines: Screenshot of Groove HQ emails

2. THE LESSONS EMAIL

Formula: [Number] Lessons [I/We] Learned by [Action You Took]

Example: 7 Lessons I Learned Doubling Sumo’s Blog Traffic From 100,000 To 200,000 Visitors In One Month

Best Email Subject Lines: Screenshot of email from Tim Ferriss

3. THE HOW THEY DONE IT EMAIL

Formula: How [Type Of Person] did [Action They Took]

Example: How 35 influencers grew their sites from 0-10K visitors

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

4. THE BEST-OF EMAIL

Formula: The Best Of [Topic]

Example: The best time to send emails

5. THE YOU VS. THE WORLD EMAIL

Formula: How Your [Data Point] compares to everyone else’s

Example: How your email opt-in rate compares to everyone else’s

Check out a variation of this subject line formula, with first name personalization below:

Best Email Subject Lines: Screenshot of email by Runkeeper

6. THE HERE’S WHY WE EMAIL

Formula: Here’s Why We [Something Remarkable]

Example: Here’s why we just spent $1.5 million 

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

7. THE MY BIG MISTAKE EMAIL

Formula: My Big [Topic] Mistake

Example: My big email popup mistake

8. THE AUTHORITY FIGURE EMAIL

Formula: [Authority’s Name] [Topic + Secret/Tips]

Example: Tony Robbins’ 1,000,000 website visitors per month traffic strategy 

Here’s The Authority Figure email in action: 

Best Email Subject Lines: Screenshot of email title of a The Authority Figure Email

9. THE RESULTS EMAIL

Formula: How We [Result] In [Timeframe]

Example: How we grew a site from 0 to 10k visitors in a month 

Check out this subject line being used by Drift below: 

Best Email Subject Lines: Screenshot of Drift email

10. THE URGENCY EMAIL

Formula: [Action] Now

Example: Open this right now 

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

Best Email Subject Lines: Screenshot of email from UFC

11. THE CASE STUDY EMAIL 

Formula: [Case Study] [Result of Case Study]

Example: [Case Study] Kickstarter campaign makes $15k in 28 hours 

Best Email Subject Lines: Screenshot of case study email by Sumo

12. THE HOW-TO EMAIL

Formula: How To [Achieve Desired Result]

Example: How to get 2,239 email subscribers in 117 days 

Screenshot of how-to email by Sumo

13. THE SCHOOL OF EMAIL

Formula: [Celebrity] School Of [Topic]

Example: Tony Robbins School Of Marketing 

14. THE DO THIS EMAIL

Formula: Do THIS [Benefit]

Example: Do THIS if you want more website traffic  

15. THE BRANDED NEWSLETTER EMAIL

Formula: [Name of Newsletter] [Issue #]

Example: The Sumo Email Marketing Newsletter #24 

16. THE ROUNDUP EMAIL

Formula: [Number] experts [Topic]

Example: 10 experts share their one EPIC roundup post

17. THE AVOID THESE EMAIL

Formula: Avoid These [Number] [Topic] [Pitfalls/Mistakes]

Example: Avoid these 10 call-to-action button mistakes 

You can see this subject line in action from Houzz: 

Best Email Subject Lines: Screenshot of email from Houzz

18. THE THREE-POINTER EMAIL

Formula: [Topic 1], [Topic 2], and [Main Topic]

Example: UFC, sore thumbs, and power words 

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

Screenshot of email subject line of emails from Tim Ferriss

19. THE ART OF EMAIL

Formula: The Art Of [Topic]

Example: The art of headline writing 

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

Best Email Subject Lines: Screenshot of Hiten Shah

20. THE % RULE EMAIL

Formula: The [Percentage] Rule Of [Topic]

Example: The 80% rule of testing a business idea  

21. THE MOST INTERESTING EMAIL

Formula: The most interesting [Person] in the world

Example: The most interesting ecommerce entrepreneur in the world

Here’s an example from Tim Ferriss:

Best Email Subject Lines: Screenshot of email from Tim Ferriss

22. THE CAN’T BELIEVE HOW MUCH YOU'LL LOVE THIS EMAIL

Formula: Can’t believe how much you’ll love this [product]

Example: Can’t believe how much you’ll love this List Builder app  

23. THE NORMALLY WE EMAIL

Formula: Normally We [Do Something]. You Get It [New Way]

Example: Normally we charge $500 for this advice. You get it free in our new Sumo Marketing Book 

PART TWO: SALES EMAIL SUBJECT LINES

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 marketer to master. 

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

Here are 18 subject line formulas you can use in your sales emails: 

24. THE LAST CALL EMAIL

Formula: Last call: [Name Of Product] closes in [#] hours

Example: Last call: Sumo Pro Account closes in 3 hours 

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

Best Email Subject Lines: Screenshot of email from Blinkist

25. THE PROBLEM SOLVER EMAIL

Formula: Fix Your [Problem] Now

Example: Fix Your Email Open Rates Now

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: 

Best Email Subject Lines: Screenshot of email from Onnit

26. THE TRY OUT EMAIL

Formula: Try Out [Product] For Yourself 

Example: Try out Sumo for yourself

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

Best Email Subject Lines: Screenshot of email from Byron Burger

27. THE FLASH SALE EMAIL

Formula: [Flash Sale] [Name of Product] [Discount]

Example: Flash Sale: Black Rhinos Book 50% Off 

Tribe used a variation of this subject line to promote a recent sale: 

Best Email Subject Lines: Screenshot of email from Tribe

28. THE LIMITED-TIME SALE EMAIL

Formula: [Time Left]: [What’s on offer] for [Discount]

Example: 48 hours left: 1 year of Beacon Unlimited for free

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 subject line above to promote our Beacon partnership and it resulted in a 53% open rate.

29. THE QUICK ANNOUNCEMENT EMAIL

Formula: Quick Announcement: [Topic] is here

Example: Quick announcement: The live Shopify case study is here

Best Email Subject Lines: Screenshot of email from Foundr

30. THE CALL OUT EMAIL

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

Formula: Proof That [Product] Works

Example: Proof that Sumo’s cart abandonment strategy works 

32. THE DON’T BUY THIS EMAIL

Formula: Don’t buy [Product Name] until you read this

Example: Don’t buy Sumo for your Shopify store until you read this

33. THE VERSUS EMAIL

Formula: [Subject] vs [Subject]

Example: $$$ vs % off discount

34. THE DEATH OF EMAIL

Formula: The Death Of [Topic]

Example: The death of Facebook ads

35. THE QUESTION EMAIL

Formula: How can you [Topic]?

Example: How can you grow your YouTube channel?

Brian Dean quite often uses questions in his email subject lines: 

Best Email Subject Lines: Screenshot of email from Brian Dean

36. THE “YOU” EMAIL

Formula: You, A [Desired Result]?

Example: You, an ecommerce all-star?

37. THE IMAGINE RESULT EMAIL

Formula: Imagine [Desired Result]

Example: Imagine having a full year of content planned in advance

Here’s an example of this subject line from the Natural Resources Defense Council (NRDC):

Best Email Subject Lines: Screenshot of email from Natural Resources Defense Council (NRDC)

38. THE SEASONAL DISCOUNT EMAIL

Formula: Save [Discount] [Items] This [Season]!

Example: Save 25% on shoes this spring!

Best Email Subject Lines: Screenshot of email subject line

39. THE "YOU AREN’T USING" EMAIL

Formula: The most surprising [Product] features you aren’t using

Example: The most surprising Sumo features you aren’t using

40. THE CAN’T BE WRONG EMAIL

Formula: [Number] People Can’t Be Wrong

Example: 5,000 people can’t be wrong 

41. THE USE THIS EMAIL

Formula: Use This [Thing]

Example: Use these WordPress plugins

PART THREE: COLD EMAIL SUBJECT LINES

If you’re running a business, you’ll have to send cold emails. 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 18 formulas you can use for cold email subject lines: 

42. THE I FOUND YOU THROUGH EMAIL

Formula: I Found You Through [Contact First Name] [Contact Last Name]

Example: I Found You Through Mark Zuckerberg

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

43. THE BETTER WAY EMAIL

Formula: A better way to [achieve goal]

Example: A better way to capture email subscribers who buy

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

Best Email Subject Lines: Screenshot of email from Better Way

44. THE REAL REASON EMAIL

Formula: The Real Reason [Target Market] [Attracted To Product/Topic]

Example: The real reason Shopify store owners use Sumo

45. THE TRUTH EMAIL

Formula: The Truth About [Topic/Person]

Example: The truth about Sumo.com discount codes

Onnit used this subject line formula in a recent campaign: 

Best Email Subject Lines: Screenshot of email from Onnit

46. THE PROBLEM EMAIL

Formula: The Problem With [Insert Problem]

Example: The problem with your Pinterest marketing strategy

47. THE SPECIFIC EVENT EMAIL

Formula: [Event Name] [Reason for Messaging]

Example: SumoCon 2020 Tickets 

48. THE LET ME… EMAIL

49. THE RIGHT PERSON EMAIL

Formula: [Name], are you the correct contact?

Example: Bob, are you the correct contact?

50. THE CAN I HELP EMAIL

Formula: Can I Help with [Topic/Problem]?

Example: Can I help increase your traffic from affiliates?

51. THE IDEA EMAIL

Formula: Idea to help solve [Problem]

Example: Idea to help get people referring friends to your business

52. THE MEET THIS NEW THING EMAIL

Formula: [Name], meet [your new product/feature]

Example: Dean, meet FAM!

Best Email Subject Lines: Screenshot of email from Dean Yeong

53. THE CONTENT SHARE EMAIL

Formula: [Name], just wanted to share this [content] with you

Example: Ash, just wanted to share this video on lowering cart abandons with you

54. THE YOUR GOAL EMAIL

Formula: Will you reach your [Goal]

Example: Will you reach your email list growth goal

Best Email Subject Lines: Screenshot of email from Nutmeg

55. THE FOUND YOU ON EMAIL

Formula: Found you on [network/website]

Example: Found you on Twitter

56. THE HELPER EMAIL

Formula: [Topic] got you [emotion]? Can I help?

Example: Increasing your website traffic got you down? Can I help?

57. THE GREETING EMAIL

Formula: [Time of day], [Name]

Example: Afternoon, Ash

58. THE YOU ROCKS EMAIL

Formula: [Company/name] rocks!

Examples: Sumo’s blog rocks!

Best Email Subject Lines: Screenshot of email subject lines from Dean Yeong

59. THE CHAT EMAIL

Formula: [Name], I’d love to chat about [topic]

Example: Dave, I’d love to chat about ecommerce pricing

PART FOUR: FOLLOW-UP EMAIL SUBJECT LINES

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

80% of non-routine sales occur only after at least five follow-ups. And 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 14 formulas you can use for follow-up email subject lines: 

60. THE WE DISCUSSED EMAIL

Formula: Here’s the [topic] we discussed

Example: Here’s the quote we discussed

61. THE THANKS FOR YOUR TIME EMAIL

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

Example: Chris, thanks for your time today

62. THE WE STILL ON EMAIL

Formula: We still on for [Date/Time]?

Example: We still on for Tuesday?

Here’s a super smart variation of this email from Virgin Atlantic to follow up with people who searched for flights on their website:

Best Email Subject Lines: Screenshot of email from Virgin Atlantic

63. THE WAYS TO GET STARTED EMAIL

Formula: [X] Ways to [Experience Growth] with [Product]

Example: 5 Ways to Kill Your Next Workout With Sumo Protein

64. THE I FORGOT EMAIL

Formula: I forgot to mention [Topic]

Example: I forgot to mention how I get more orders with a GWP strategy

65. THE WE HAVEN’T EMAIL

Formula: We haven’t [Action]

Example: We haven’t stopped giving instant discounts

66. THE MISSED YOU EMAIL

Formula: Missed you, how’s [Day]?

Example: Missed you, how’s Thursday?

67. THE TO-THE-POINT QUESTION EMAIL

Formula: What’s your [Question]

Example: What’s your calendar look like next Wed at 3 pm?

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

Best Email Subject Lines: Screenshot of email from Justin Jackson

68. THE FOLLOW-UP ‘RE:’ EMAIL

Formula: Follow Up re: [Topic discussed]

Example: Follow Up re: Mobile popup strategy

69. THE AWESOME TO MEET YOU EMAIL

Formula: Awesome to Meet You at [Event/Place] [Date/Time]

Example: Awesome to Meet You at SumoCon Last Week

70. THE TOUCHING BASE EMAIL

Formula: Touching Base Regarding [Topic] [Date/Time]

Example: Touching Base Regarding Our Pitch Yesterday

71. THE QUICK CHECK-IN EMAIL

Formula: Checking in on [topic]

Example: Checking in on our one-page business plan

72. THE STEVE JOBS EMAIL

Formula: [One more thing] about [topic]

Example: One more thing about our ecommerce strategy

73. THE SOMETHING BAD HAPPENED EMAIL

Formula: Hey, I [something bad that gets attention]

Examples: Hey, I messed up.

PART FIVE: TRANSACTIONAL EMAIL SUBJECT LINES 

Chances are your company sends a ton of transactional emails. They are emails like order confirmations, receipts, and billing reminders.

As these emails are usually triggered by customer actions, like making a purchase or signing up for your product, transactional emails have an open rate of eight times higher than normal emails.[*]

Best Email Subject Lines: Screenshot of bar chart showing the effectiveness of transactional email subject lines

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

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

74. THE WELCOME EMAIL

Formula: Welcome to [Brand/Name]!

Example: Welcome to Sumo!

Here’s an example welcome email: 

Best Email Subject Lines: Screenshot of Wealthify email

75. THE LET’S GET STARTED EMAIL

Formula: Welcome to [Brand/Name] - [Action encouraged]

Example: Welcome to Warby Parker! Try on some glasses now

76. THE THANK YOU EMAIL

Formula: [Business name]: Thank you for being a customer

Example: Dollar Shave Club: Thank you for being a customer

Check out an example thank you email from Medium below: 

Best Email Subject Lines: Screenshot of email from Medium

77. THE REMINDER EMAIL

Formula: [Date/Time] You [Action took]

Example: Last Wednesday You Added Nike Running Shoes to your basket

78. THE ORDER EMAIL

Formula: Your order of [product name]

Example: Your order of Spiderman 3

79. THE NEXT STEPS EMAIL

Formula: Welcome to [product name] - [next steps]

Example: Welcome to Uber - here’s how to take your first ride

80. THE ACTION REQUIRED EMAIL

Formula: Action Required: [Task]

Example: Action Required: Confirm Your Email Address

Best Email Subject Lines: Screenshot of Action Required email type

BENCHMARKING YOUR EMAIL OPEN RATES

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

Here are the average email open rates across 45 industries:[*]

Industry
Average Open Rate
Average Click Rate
All non-labeled accounts
22.71%
2.91%
Agriculture and Food Services
23.31%
2.94%
Architecture and Construction
22.51%
2.51%
Arts and Artists
26.27%
2.95%
Beauty and Personal Care
16.65%
1.92%
Business and Finance
21.56%
2.72%
Computers and Electronics
19.29%
2.08%
Construction
21.77%
2.26%
Consulting
20.13%
2.49%
Creative Services/Agency
21.39%
2.66%
Daily Deals/E-Coupons
15.06%
2.23%
E-Commerce
15.68%
2.01%
Education and Training
23.42%
2.90%
Entertainment and Events
20.51%
2.36%
Gambling
21.62%
3.30%
Games
21.10%
3.66%
Government
28.77%
3.99%
Health and Fitness
21.48%
2.69%
Hobbies
27.74%
5.01%
Home and Garden
21.60%
3.03%
Insurance
21.36%
2.13%
Legal
22.00%
2.81%
Manufacturing
19.82%
2.18%
Marketing and Advertising
17.38%
2.04%
Media and Publishing
22.15%
4.62%
Medical, Dental, and Healthcare
21.72%
2.49%
Mobile
19.29%
2.27%
Music and Musicians
21.88%
2.94%
Non-Profit
25.17%
2.79%
Pharmaceuticals
18.58%
2.25%
Photo and Video
23.24%
3.23%
Politics
22.94%
2.37%
Professional Services
21.94%
2.55%
Public Relations
21.02%
1.98%
Real Estate
19.17%
1.77%
Recruitment and Staffing
21.14%
2.53%
Religion
27.62%
3.16%
Restaurant
19.77%
1.34%
Restaurant and Venue
20.39%
1.40%
Retail
18.39%
2.25%
Social Networks and Online Communities
21.06%
3.32%
Software and Web App
21.29%
2.45%
Sports
24.57%
3.09%
Telecommunications
20.92%
2.27%
Travel and Transportation
20.44%
2.25%
Vitamin Supplements
15.03%
1.62%

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% - 28% range, you can be confident that you’re doing well.

3 BONUS TIPS TO IMPROVE YOUR EMAIL SUBJECT LINES

You got the email open benchmark, and the above email subject line formulas and examples 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 (since removed from their site) found that 56% of brands using emojis in their email subject lines saw a higher open rate on their emails.

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

Best Email Subject Lines: Screenshot of top 15 emojis by subject line appearances

2. TEST VARIOUS LENGTHS

For most businesses, there’s no direct coloration between subject line length and open rates. But you should think about where your subscribers are opening their email.

Based on an email marketing stats report by Litmus, the majority of your opens came from mobile devices and tablets.[*]

Best Email Subject Lines: Screenshot of graph showing the percentage of which platforms that emails are open from

With smaller screens, you need to ensure your subject line fits within the allocated space. The rule of thumb is to keep your subject line between 30 and 60 characters. 

3. USE TIME-SENSITIVE WORDS

Using time-sensitive words like “urgent” and “important” can result in much higher open rates. Data from Mailchimp (since removed from their site) proves it: 

Best Email Subject Lines: Screenshot of the effectiveness of certain keywords in email subject lines

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. 

SKYROCKET YOUR OPEN RATES WITH IRRESISTIBLE EMAIL SUBJECT LINES 

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

If you’d like to download a spreadsheet with all the subject line formulas and examples, so you can print it out to reference, click on the button below.

Get The Free Email Subject Line Worksheet