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How to improve your email marketing open rate by 40%

Email marketing might be the cheapest, most efficient form of marketing – but only if people open the emails. It’s heart-breaking to spend ages crafting concise, engaging email newsletters with the right messaging and links – only for nobody to open them. 

We’re here to help. We’ve tried these methods ourselves and found that they can increase email open rates for clients by 30% in a matter of weeks, and 40% in months. 

Why do email open rates matter? 

In most cases, email open rates link directly to your bottom line. The more people who open your email, the more people are likely to click through to your site – which means more opportunities to sell your product.

But few people will buy on just their first click, so the key is consistency. Try these out for a few months, and your email open rates should rise significantly.

To get an idea of what a ‘good’ or ‘bad’ open rate is for your industry, check out this handy guide from Mailchimp

  1. First impressions – don’t be too clever or too basic
  2. The vital three words – make the start of your subject line impactful
  3. The 7-12 principle – optimum subject-line word counts
  4. The two-hour rule – build in thinking time
  5. The double-checker – tools that can help
  6. The 100-word goal – keep your message brief
  7. The 40% clincher – consistently deliver what your subject lines promise
  8. Our no 1 tip – get a helping hand


One of the biggest mistakes people make with their email newsletter subject lines is trying to be too clever.

Wordplay and cultural references work well in newspaper, magazine and book headlines – but that’s because they have photos, illustrations or introductory text right next to them, which explains the concept more fully. 

You don’t have the luxury of playfulness with email subject lines. People are busy and want to know what this email is about in two seconds, so make it easy for them to grasp the point of your email fast.

But the next biggest mistake? Not being clever enough! 

If you are too straightforward and simplistic in your subject line, only your mum will open it. Avoid the blatantly obvious and dull subject lines, such as ‘Monthly Email Newsletter’ or ‘Company News’. People will only open those to unsubscribe. 

Finally, don’t forget to think about who the ‘sender’ is for your newsletter. People will open emails from someone they know and trust more often than from a generic company, particularly if it’s one they aren’t familiar with.


While longer headlines perform better, that’s only if the first three words grab your customer enough to convince them to read on. 

Almost everyone reads emails on their phone now. Some will also read them on a laptop or desktop, but you need to write for the smallest size and then expand for the larger. 

That means the first three words are vital. Mobiles will only display a few characters, so make those first few words count.

How do you do that? The old editing hack is to flip the sentence around and move the most interesting words to the front. This will require some editing, of course, but here’s an example of how that works.

Take this subject line: “We have developed a car powered by water, a concept that could help save the planet.”

On a mobile, all you’ll see is ‘We have developed’ – and most readers will just scroll on past. 

Flip it around and edit this to increase opens: “Water-powered cars could save the planet – and we’ve made the first.”

On mobile, all you’ll see is “Water-powered cars…”, which is intriguing enough to make many more people click ‘open’.

And once you think you’ve nailed those first few words – and your full subject line and preview – just run it through a subject line tool to see what it will look like on a phone. This can help you avoid some embarrassing results.


Ensure your subject line is long enough to say something meaningful – but short enough to make sense on mobile. 

If you look up ‘best email subject line length’, you’ll get all sorts of answers. Some say three to five words. Others claim 9-12 words

In our experience, when it comes to email subject lines, shorter isn’t usually better. In fact, the best-performing emails we’ve seen are those with 7-12 words. Of course, character count comes into it, and a 12-word subject email will contain mostly shorter words and be fewer than 55 characters long.


Allow yourself at least two hours to work on a subject line.

But don’t panic. You will not (usually) be toiling away for the full two hours. 

Instead, you should spend about 20-30 minutes working up various first drafts of your subject line.

Now step away from the email. Do something else, and come back to it an hour later. 

Repeat as necessary until you have a subject line you’re happy with. 

Sometimes, you’ll nail a good one quickly. Other times, it can take all day – brainstorming, tweaking, thinking, starting over – and repeat. 

On average, it takes the team here at Proof Content two hours – about 30 minutes of actual writing, and 90 minutes of mulling it over in the back of our minds as we work on other tasks.


Once you have your email, run it through a “headline analyser” or a “subject-line analyser”. You can find several of these online just by Googling.

A few we like are Coschedule and SendCheckIt – but there are heaps, so it’s worth trying to a few to see which works best for you.

Most are free – but all must be taken with a big pinch of salt as they’re quite limited in scope, and sometimes their algorithms are based on older data, which isn’t always so effective. 

But playing around with these can help hone your subject line writing skills. If the analyser says your subject line isn’t going to do well, it’s usually right, so just try variations until you find one that will work better. 

Most email newsletter platforms have their own basic subject line analysers built-in, but they’re often quite basic, so it’s always worth trying at least a couple of them for balance.

We ran a few through the subject-line analysers – and through Zurb for the mobile preview. They sometimes disagree on what will work and what won’t, but if at least two of them think you have a winning subject line, they’re probably right.

For the email newsletter we sent with this blog, we abandoned a few options that one or more of the analysers thought were poor, including “Increase email open rates with these tips”, “Want more people to open your emails?” and “How to boost email open rates by 40%”.

We opted for the one they all agreed was strong: “Improve email open rates with our step-by-step guide.”

We’ve tested these against real data in the past, and they are far from infallible, but they generally steer you in the right direction.


Nobody wants to read long emails, so keep yours short and snappy. 

You want to give your audience enough information to convince them to click through to your blog, product, special offer or webinar, and you only have a few seconds to do this.

We’ve found that keeping emails shorter than 100 words is about right. If you’re sharing multiple links to blogs, deals, etc, then you can go a little longer, but break it up with different titles and sections. 

If you’re not sure what 100 words looks like, it’s the section you’ve just read, from “Nobody” to here.


If people click that killer email, you must deliver what the subject line promised. This is the most important element that will lead to a long-term boost in email open rates.

Take in all the tips above, and you’ll already see an increase. But real change comes as your newsletter audience opens an email, and finds that you provide them with what the subject line promises. 

Whether it’s a sales email or a content-led one, if the click-through disappoints, they will not open your emails again, no matter how compelling the subject line. You’ve broken their trust. 

For sales emails, that means if you’re promising ‘Hotel suites for £10’, but the link takes you to a page where the cheapest suite is £50, they won’t click your next email. No matter how great the subject line.

For content-led emails – the kind that builds audience trust and increases engagement and long-term sales on your site – the links in your email must take them to blogs that deliver insightful, engaging content. Ill-informed, badly researched blogposts that are all gloss and no weight will not see readers opening your emails again. 

Always deliver content that is genuinely interesting and insightful, with an email subject line that grabs readers straight away, and you’ll see your email rates steadily climb over the months. 


Most people aren’t writers and editors with years of experience. Doing all of the above will help – but only if you’re diligent and give it the time it needs.

To fast-track the process and increase your email open rates consistently, you need great subject lines backed up by well-researched blogs, product pages, offers and websites – written by experienced professionals. 

How to improve your email marketing open rate by 40%

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