6 tips for writing great email subject lines

Posted on 23/04/2015 by Team Hallam

Just as writing great headlines can attract more readers to your blog, a well-written email subject line can increase the number of subscribers who will actually open your email messages.

Here are my top tips for crafting email subject lines that won’t get ignored.

Keep it short

In most browsers, email subject lines are cut off after about 60 characters. Mobile devices allow for even fewer characters, so try to make your point in under eight words. You may even find that a subject line with only one or two words stands out in most people’s cluttered inboxes.

I regularly check my emails on my mobile phone. I recently received the email below:

long subject line - mobile

As you can see, the subject line is far too long. I am being asked to try a bag containing a mystery product. The subject line is doing nothing to make me want to find out more, so I choose to ignore this email.

However, if you look at the same email message when opened on a desktop computer, I have a completely different user experience. I like coffee. I can try a bag of freshly roasted Pact Coffee for just £1. I’m going to open the email and find out how I can claim this amazing offer.

long subject line - desktop

With 66% of emails being opened on a smartphone or tablet, and with mobile traffic growing year on year, the importance of subject line length should not be underestimated.

Ask a question

Asking a question in your subject line gets your recipient thinking. Think of it as a means of starting up a dialogue that can only be continued through opening your email to find the answer. For best results, try asking questions that target the sort of problems your customer or prospect is likely to encounter, and for which they need a solution:

  • Do you want to improve your email open rates?
  • Local knowledge panel not showing on Google?
  • Is your website ‘mobile friendly’?

These types of subject lines are effective, as the recipient can relate to them and are drawn to the prospect of learning more. Just make sure you don’t forget to answer the question in the content of the email.

Set expectations

Use your subject line to let recipients know what they can expect to see when they open your email.

  • Use lists – 3 ways to improve your email open rates
  • Create ‘how to’ or ‘tips’ emails – how to improve your email open rates
  • Highlight offers – get your free email marketing benchmark report

A key part of this is to also make sure your subject line is relevant to the content inside the email. Always deliver on your promises. If you say there are three tips in the subject line, include three tips in the copy!

Use humour

Humour is a great tool to drive open rates and get your subscribers to engage with your content. Here are some great examples of how humorous subject lines have been used that you can use as a source of inspiration.

A few warnings, though, when using humour:

  • Don’t be offensive
  • Don’t lose your company voice
  • Use it sparingly – it’s only one of many subject line writing techniques

Create a sense of urgency

These types of subject lines encourage recipients to act now. FOMO, the fear of missing out, is a great way to build excitement and drive email opens. The most popular way that a lot of organisations do this, is by including words and phrases such as:

  • Last Chance
  • Today Only
  • 24 Hour Deal
  • Exclusive

You can see some examples of how some of the organisations I am a customer of have employed this tactic to make their emails stand out in my inbox:

subject lines with a sense of urgency

Get personal

Personalisation is a great way to increase open rates. According to an Experian Email Marketing study, emails with personalised subject lines have 26% higher unique open rates. You can personalise your subject lines by either using the recipient’s name, or the recipient’s company’s name. The image above, again, highlights how EE and Amazon use this tactic to drive email opens:

Rainu meet our best ever offer for iPad Mini

Rainu Bhele: Free Kindle Book

Tread carefully when it comes to personalisation. If your email database does not feature your customers’ most up to date details, you might find personalisation has a detrimental effect on your open rates.


These tips are just some of the ways that you can increase your email open rates. But as vital as it is to encourage people to open your emails, it’s even more important to ensure that, once they’re in, they like what they see. Even if your email subject lines are absolutely irresistible, if you consistently deliver underwhelming content, your customers will lose interest.

Use good subject lines in conjunction with high quality, relevant content to keep your open rates consistently high, and drive more conversions.

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6 tips for writing great email subject lines

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