How to write a killer email subject line

by The Salmat Team
31 March 2017
How to write a killer email subject line
Billions of emails are sent worldwide every day, find out how your subject line can set yours apart.

While there are no absolute rules to crafting a great email subject line, there are some proven ways to get results for popular types of marketing campaigns. They all seek to engage a recipient and communicate that valuable information is just a click away.

So, when you want to write email subject lines that get results, try these helpful tips to pull off that killer email campaign.

1. Avoid spam filters

There’s no point writing a killer subject line if your email never reaches its intended recipient because of a spam filter.

While staying clear of spam filters is increasingly difficult, it helps to avoid words and phrases we know will trigger them – well-worn phrases like 'order now', 'save $', and 'subject to credit', and many more on this list.

Spam filters also scan for certain types of expressions. So, avoid email subject lines in ALL CAPS and don’t go overboard on the punctuation, like concluding your subject line with consecutive exclamation points!!!!

2. Make it personal

If you know the name of the intended recipient, reflect this in the subject line. It's a good way to increase your open rates – recent statistics show that emails with personalised subject lines are 26 percent more likely to be opened.

Personalising your subject line could mean using the recipient’s first name as well as their company's or organisation's name for more cut-through.

3. Make it mobile-friendly

With around 50 percent of emails now read on mobile phones, you need to make your subject line compelling for mobile devices.

This means keeping it extra snappy – Outlook only allows around 40 characters on mobile for a subject line, and Gmail 75 characters.It's crucial to make your offer specific and relevant.

4. Make it urgent

Ideally, the recipient will feel compelled to open your email as soon as they see it. Where possible, the subject line should urge them to act now.

Some techniques include: tweaking your subject line so it sets a deadline , or pairing your call to action (CTA) with an urgent word, for instance combining 'claim your coupon' with 'now', or 'start saving' with 'today'. Co-schedule has created a list of "power words" to include in your subject lines to prompt action.

Email marketing and fashion ebook

5. Stay on brand

Even if your email isn't opened by the intended recipient, it’s likely that they will see the subject line in their inbox. So, it’s important to align your subject line with your brand's tone of voice. If your brand has a playful tone of voice then you could potentially use emojis and slang, while a B2B brand may choose a more professional tone of voice. Whatever your tone of voice, the important thing is to be consistent.

6. Include a call to action

A powerful strategy is to include a CTA in your email subject line – it can be as simple as using words and phrases like 'Go!' or ‘Talk to us'.

Alternately, you can play with mystery, surprises, and must-open invitations but, irrespective of the technique, ensure you deliver when the reader does click through.

7. Don't forget the pre-header text

Complement the subject line with the pre-header text. This can appear above the banner or included as a hidden field so that it just appears in the recipient's inbox next to the subject line. This is another opportunity to intrigue the reader so make sure the copy is written in the same tone of voice as the subject line.


There’s no one-size-fits-all approach to writing the perfect email subject line. You can use A/B testing [ to see what works best for you, and experiment thoroughly before launching your next email marketing campaign.

Undoubtedly, finding the right subject line that gets results takes time and effort, and is a process of discovery but, by keeping in mind these best practices, you’ll be heading in the right direction.

Want to become an expert in email marketing? Contact us today on 1300 725 628 to find out more and get a quote.

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About the author
The Salmat Team

Salmat is a leading Australian marketing services provider. We help clients connect with their customers, week-in, week-out. Salmat's unique combination of targeted letterbox and online marketing channels enables clients to Reach, Convert and Serve their customers. We also provide a wide range of back office solutions, through our Philippines-based Managed Services business.

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