Best Email Subject Lines: 6 Ways to Write Catchy Subject Lines and Boost Open Rates

This is a guest post by SendFox customer and video producer Garth Dew. He uses SendFox for his email newsletter about creativity, marketing and entrepreneurship. Find the best email subject lines below!

So, you want to build a powerful email list. Great idea!

But starting your list is only the beginning.

To get results, you’ll need your subscribers to OPEN your emails.

And that’s not as easy as it sounds…

The average email marketing open rate is around 20% (source). That means, on average, 80% of your subscribers are not opening your emails.

Your audience’s inboxes are flooded with other emails fighting for attention. 

So, if you want to get your emails opened, they need to stand out from the crowd.


The subject line placeholder in SendFox
The subject line area of SendFox.

The subject line is the first thing people see when your email lands in their inbox.

And the subject is so important that 35% of email recipients open emails based on the subject line alone.

If you optimize your subject lines, you win big — and you can dramatically increase your open rates, click rates, and more.

So, let’s look at 6 ways to write the best email subject lines.

These are REAL examples and strategies that your audience won’t be able to resist.

Best Email Subject Lines: 6 Strategies That Really Work

Strategy #1 – Curiosity

Curiosity is a powerful marketing tool.

People want to know the answers to their biggest questions — and can’t resist a good curiosity email subject line.

You can make subscribers curious by doing three key things:

  1. Asking a question. Questions in subject lines lead a reader to opening their email to find out the answer.
  2. Offering something interesting. In the land of dozens of emails that all blend together, it’s important to stand out.
  3. Saying something bizarre. Just like those weird facts you read online, weird facts or a bizarre statement in a subject line can be a great way to get opens.

Here are a few examples of curiosity subject lines from our inbox:

Curiosity subject lines
Examples of curiosity subject lines.

Strategy #2 – Personalization

A study by Yes Lifecycle Marketing found non-personalized subject lines had open rates of 14.1%… compared to 21.2% for email personalized with names.

Bottom-line: Personalize your subject lines for better results.

An easy way to personalize is by using the subscriber’s name in the subject line.

To do this in SendFox, use the {{contact.first_name}} personalization tag in your subject line.

Combine personalization and curiosity to really up your email marketing game, like the example below:

Email personalization
Combine personalization and curiosity for the best results.

Here are some examples of personalisation from big brands you know:

Personalization examples
Great examples of personalization subject lines.

Strategy #3 – Humour

It doesn’t matter what you’re emailing about — if you make your readers laugh with your subject lines, they’ll look forward to your emails.

One of the best ways to do this is to use puns and pop culture references. The AppSumo emails have some of the best.

Check out these pun-tastic subject lines AppSumo has used to promote new software offers:

  • Suite dreams (are made of this)
  • The Fresh Prince of LMS
  • Four-ggedaboutit
  • Bring home the Beacon
  • Don’t lose your (Metri)cool

Here are a few more examples from other brands:

best email subject lines
The best email subject lines for… socks?! Hey, you have to be funny sometimes.

Strategy #4 – Contrarian

Using contrarian statements is another great way to arouse curiosity.

The aim is to make your audience think, “What the…?!”

The piqued interest convinces the reader to open the email to understand the full context of the contrarian statement.

To make a contrarian subject line, take two opposing ideas or contrasting statements and put them together.

This works especially well with commonly-held beliefs or “accepted” ideas. If you provide contrasting information to something that most people believe, the shock will cause a lot of people to open.

Here are a few examples:

Contrarian email subject lines
Contrarian email subject lines get your readers’ attention.

Strategy #5 – Clear-Cut Benefit 

Sometimes you don’t need to get creative. You can tell it to your audience straight. Simply by stating the benefit of opening the email in the subject line.

This type of subject line is very effective if you are teaching something or sharing useful information.

If you have multiple pieces of content in your email, picking the first item can be an easy way to pick a subject line to use.

This approach usually gets a good response on my list — averaging a 50% open rate compared to 30% for other types of subject lines.

Check out some recent examples from my inbox:

Clear-cut benefit email subject lines
Examples of clear-cut benefit email subject lines.

Strategy #6 – Celebrity 

Using recognisable names and references in your subject lines can pique interest in the same way gossip magazines and tabloids use headlines. 

The master of this approach is legendary email marketer Ben Settle.

The 4 examples below are from his free newsletter, which is worth subscribing to if you want some daily subject line inspiration.

  • Once upon a time, Grant Cardone had a sale
  • Trump the Aristotle of copywriting?
  • The Steve Jobs prophecy
  • X-Men actress admits getting hired ain’t about talent or skill

You don’t have to be an email marketing wizard to create the best email subject lines.

Following a few simple principles, you can create subject lines in seconds that help skyrocket your email open rates:

  1. Curiosity. Tease the content with a short subject line.
  2. Personalization. Use your subscriber’s name in a subject line.
  3. Humour. Give some personality, and make jokes — people open what makes them laugh.
  4. Contrarian. Take two opposing viewpoints, and turn it into a subject line to really entice.
  5. Clear-cut benefit. Keep it simple and tell readers exactly what they’ll get when they open.
  6. Celebrity. Use recognizable names and readers will want to open to find out.

Get a more affordable, easier-to-use email software to try your new subject lines. Get SendFox starting at $49 one-time cost. Pay once, email forever.

Check out this guide on how to improve your open rates and keep your deliverability high – Email Deliverability: How to Improve Email Open Rates.

Ever considered incorporating Employee Engagement tool? These have become very popular lately, check out the solutions here.

How to 2x Your Email Results with Email A/B Testing

This is a guest post by copywriter Will Ward who uses SendFox for his business switchTop Keyboards and explains how to do the A/B testing in SendFox.

There’s a ton of advice out there on email marketing.

“Always use a P.S.!”

“Write in a conversational tone!”

Some of it can even get a bit weird…

“Use power words to ‘hypnotize’ your readers!”

If you’ve ever done any kind of online marketing, you know these tips can be like crack.

Personally, I know that changing just ONE word on my website has driven tens of thousands of dollars in extra sales. 💵

And the same can happen for you.

It’s important to take ACTION — and see what helps you get results for your business.

Enter the simple skill of email A/B testing…

How to Run Quick Email A/B Testing with SendFox

I first heard about A/B testing from the book In The Plex about the early days of Google.

Google execs would debate what color to make the links and thousands of other small changes that could have HUGE impacts.

To test objectively, they would test changes on a fraction of their traffic and compare it to the unchanged version.

Now you may be thinking, “sure it’s easy for Google to do tests when they have school busses full of PhDs and billions of searches per month.”

I once thought the same thing — but now I realize that that’s a dangerous limiting belief.

No matter your size, not testing can be costing your business in lost sales every time you send an email with SendFox.

And testing isn’t hard.

There are a ton of free A/B testing tools out there, and you don’t need a massive list to get valid results.

Now, SendFox doesn’t have a built-in A/B testing feature. But it’s easy to split your list and use it as your email testing platform.

Here’s how to do it:

  1. Download your list from SendFox [SendFox help article]
  2. Use Excel to randomly split it into two sub-lists [Screencast video]
  3. Upload them back into SendFox as two separate lists [SendFox help article]

Three Little Tests

Now that you can test, what should you test?

Once you get into persuasion and copywriting it’s easy to keep reading book after book.

And pretty soon you end up with a bookshelf that looks like this:

My persuasion books for email A/B testing
My persuasion books.

But one thing I’ve found is that a lot of persuasion tips are not universal.

So I went back to my stack of books and made a list of every tip I could find and started testing them, one by one.

I want to share three results I’ve gotten so far.

These were all run using my SendFox testing lists to a small ecommerce store selling parts for mechanical keyboards.

A/B split testing different email subject lines in SendFox
Split testing different subject lines.

I learned this trick from copywriter Ian Stanley. The idea is, when making your offer, it’s more persuasive to use the word “when” instead of “if”. For example:

  • Less Persuasion: “Get 15% off if you spend $50″
  • More Persuasion: “Get 15% off when you spend $50

So, using my test lists in SendFox, I ran a limited time sale offer using the two headlines above.


This one surprised me. Using “when” got twice the number of sales and pulled over twice the sales volume as the “if” email.

Ian was right — use “when” instead of “if” for better results!

Test 2. Personalized “From” Field

Here’s a peek at my Gmail “Promo” tab this morning:

My inbox this morning with all the different subject lines
My inbox this morning.

There are some brands emailing me.

There’s the finance site Seeking Alpha, and the industrial equipment site IronPlanet (where I go to live out my childhood dreams of owning a tractor).

But you’ll also see some personalized senders, with a [name] from [brand] formula. Like my buds “Ben from Flippa” and “Lizzie from Khan Academy.”

I’ve read the advice in several places that a “real name” email persona works better, but I was curious to test it myself.

I sent a standard ‘product back in stock’ email to my list. Half got the email from “switchTop Keyboards” (our brand) and the other half got the email from “Will @ switchTop.” That was the only change.


The personalized version saw a 5% lift in open rates.

If you’re regularly emailing your list, this is one of those “base hit” tweaks. It costs you nothing but lets you eke out a steady gain that will keep compounding in future emails.

There are not a lot of areas in life where you can get a “free lunch” 5 percent, but email is one of them.

Test 3. Does Free Stuff Sell?

A recent A/B testing email I sent to my audience.
A recent email that I sent customers of one of my brands.

Influence by Robert Cialdini is a classic book on persuasion.

One of his principles is the norm of reciprocity.

Simply put, the idea is that giving out free stuff can help you sell because it triggers a powerful social norm to repay an act of kindness.

Now, this sounds great in a perfect world…

But if you’ve ever given out free stuff, you know there are a TON of freebie seekers who are happy to take the sample but never buy.

So I was curious to see if a free bonus would drive more sales.

When I bought the business a few years ago, one of the most requested things was stickers.

So I had a bunch of stickers with our logo printed up and I sent a “Can I mail you a free sticker?” email to half my list.


The sticker offer email got a 56% open rate, which is way above the list average.

I then mailed the stickers, followed by one of our normal product restock alert emails.

So, did the sticker-offer-getters buy more stuff?

The short answer is no. They bought almost exactly the same amount of stuff.

Now, before I pump my fist in the air and shout “myth busted” on this test, a few notes:

  1. I got a ton of emails saying they loved the stickers.
  2. There’s probably some brand value to having a few dozen of our stickers on people’s laptops out there.
  3. Who’s to say that these customers won’t be higher value in the long-term?

Once you get beyond very black and white tests like “which subject line got opened more,” things can get murky real fast.

Testing is not a license to turn off your big picture judgement.

A Warning (and Invite)

Now I want to be really clear about something.

The goal of my testing project is not to arrive at “The 30 Persuasion Hacks that REALLY Work” or some B.S. like that.

Trying to apply a bunch of persuasion “hacks” from some book to your marketing project is a great way to sound inauthentic and scammy.

The real goal is to get better at the meta skill of testing.

Learning how to run a bunch of experiments fast and cheap so that you can find out what types of offers and appeals work for your situation.

If you’d like to read more about marketing and persuasion testing, you can join my new email list that I’m calling the “Underground Persuasion Lab.”

I run one test (sometimes on my own businesses, sometimes affiliate products, sometimes other lists) and write up the results in a weekly email.

If this sounds like your cup of tea, join me here. (And yup, this uses a SendFox form).

Once you’re on the list, I’ll send you my full list of persuasion “hacks” that I’m testing (42 so far).

And you’ll also get email updates about each new test when it runs — so you can take the same lessons into your emails on SendFox. Happy testing!

When you’re done with A/B testing, be sure to check out this great article on How to Write the Best Email Subject Lines for even more conversions.