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The email subject line best practices to increase your open rates

3 mins read

When you need email advice, it can feel like a mammoth task trying to find the answers you need. With suggestions flying from every angle, how are you supposed to know what’s the right thing to go with?

We recently attended two different talks on email subject line best practices. We were given a wide range of advice, but a lot of it was conflicting, so I’m going to break it down for you.


A quick overview

35% of email recipients open an email based on the subject line alone. So, as you might have guessed, getting them right is a pretty big deal. Subject lines give your audience a reason to check out your content, increasing the chances of that all-important click-through rate.

Emojis? Offers? Question marks? Caps? How long is too long? These are all questions you might ask yourself when sitting down to write your latest email subject lines and you don’t know where to start. Don’t panic; you’re not alone.

Cutting through the noise in someone’s ever-growing inbox can be a tricky task to master, but here’s an in-depth look at the best practices you need to follow to make sure your subject lines hit the sweet spot every time.


Don’t neglect email

There’s a reason why investing time in email subject lines is important. Even though there are even more marketing channels than ever before, email still comes out as one of the best, no matter what generation you’re speaking to.

Global email marketing market was valued at $7.5 billion in 2020 and is projected to increase to $17.9 billion by 2027. Yep, pretty impressive stuff. And when it comes to that all-important ROI, on average, email returns the highest ROI for marketers, beating social media and other channels by a country mile.

So with all this in mind, the last thing you want to do is disengage or alienate your audience.


Get personal

Personalisation is key. This isn’t just about using the customer's name in the subject line — pretty basic practice these days — but it’s more about breaking down your audience into segments based on interests, locations, activity and more.

On average, there’s a 760% increase in revenue when using segmented campaigns, which just goes to show that the more the content appeals to a customer, the more likely they are to open it. So go ahead, make them feel special.


Timing is key

You’ve created your email, chosen your subject line and now it’s time to hit send. But hold your horses for just a second, is now really the best time to send? Getting the right timing is everything when it comes to open rates.

Put yourself in the customer's shoes — are you really going to check your emails on a Saturday night? The reality is you’ll probably be in the pub. Research shows that Fridays see the highest email open rates at 19%, compared to Saturdays with the lowest at 17%.

Regardless of whether your subject line is a piece of art, your stats will suffer if you send it at the wrong time. On the flip side, if you’re emailing about an offer or something time-sensitive, get that urgency into the subject line. Think about it, FOMO works.

Also read: 4 of our favourite email marketing examples and why they’re brilliant

Grammar dos and don’ts

This is where we experienced the most conflicting advice when we attended our recent talks. Grammar is everything and when the subject line is standing front and centre, you must get it right.

Top of the list is capitals. All lowercase isn’t the way to go, but that doesn’t mean that all caps is the better option. Keep your subject lines in sentence case — all caps makes it seem like you’re shouting and we don’t want that.

In the same vein, don’t overuse exclamation marks, either. We don’t want you to look desperate. 

And question marks? They can actually damage your open rates. If the question is too generic or not targeted enough, chances are people won’t care enough about the answer to open.


The perfect length

Getting a subject line that’s to the point, conveys your message and has personality, all within a specific character count can be tricky, but it’s essential.

Keep in mind what device your customer will read your subject line on. Most people will check their emails on mobile, so you don’t want a subject line that’s too long and the preview is cut off.


Choose your emojis wisely 🤪

The humble emoji. We all use them and we all love them, so why not add them into your email subject lines? A single emoji can speak a thousand words... Maybe not quite, but you catch our drift — and they can add personality to your copy.

But it’s key to strike the right balance. Too many, and it could switch your customers off, so make sure you aren’t going overboard.

Also read: How to use video in email automation to boost open rates


A/B test — find what works for you

Like most things, there’s no one size fits all when it comes to email subject line best practices. You might have seen an idea you love, but in reality, it isn’t going to work for you or your audience. To find out what works best for you, roll out some A/B tests. 

A/B testing is invaluable for marketers. It takes the guesswork out of content creation, allowing you to see hard, data-driven results that help you conclude what kind of content works for your brand.

Try out different subject lines, collate the results, and over time, you should figure out what kind of subject line will get your audience to click.


Learn more from those around you

Give it a quick Google and you’ll find hundreds of thousands of articles dedicated to email best practices. The key things to take away are following some basic principles, trying out a few ideas, testing them and seeing what works for you.

We’re always looking to learn new things and some of the best insights and knowledge we have found is from each other.

If, like us, you’re looking to find new ideas from like-minded people, then you need to know about LOVE INBOUND, our annual marketing event.

LOVE INBOUND is our marketing conference where you can listen to expert speakers and grow your network. In the last two events, we’ve had a range of speakers from HubSpot, Vidyard, AdRoll and more. Sounds like something you’d like to get on board with? Then register your interest below.