Just as a book is sometimes assessed on its cover, an email subject line determines its first impression and often whether it’s opened at all. DPR&Co have gathered ten tips for writing subject lines that increase the open rate of your e-mail.

1. Keep it short

Your readers must see at a glance what your e-mail is about. Long subject lines deter readers from opening.

Our golden tip: limit the subject line to 50 characters .

Many people read e-mails on a smartphone, which automatically cuts the length of the subject line. So avoid unnecessary words and focus on your core message .

2. Make it active

By using activating words, you encourage readers to do what you want them to do. Active sentences help create a visual representation in the mind of your reader, which motivates him to open the e-mail and continue reading. See the subject line as a CTA type, with the ultimate goal of generating a click.


3. Add emojis and symbols

Adding a clear visual element, such as a symbol or an emoji, can reinforce the text of the subject line and activate the curiosity of your reader. However, this only works if the symbol is a supplement to your message. Make sure you don’t overdo it.

The use of emojis also depends on the image of your company and the tone of your e-mail. In some sectors, implementing an emoji is a definitive no-go. Find out if this approach works for your target group by performing Å/B test.

4. Create a sense of urgency

“Download now”, “30% discount for early birds”, “There are only 5 seats left for the cheapest flight to New York”. These subject rules provoke a sense of urgency and scarcity, causing your reader to take action.

By emphasising exclusivity, you give your readers a gentle push for action. This makes it easier to overcome their hesitation. This type of subject line is ideal when emailing about a promotional offer.

5. Use numbers

By adding numbers to the subject line, you send a clear message about your offer. The figures set the right expectations to emphasise your offer.

A figure usually refers to a specific discount, but you can also let your subscriber know how long the discount is still valid. For example: “Only 2 days left to take advantage of our free shipping.”

6. Ask a question

Questions arouse curiosity. That is, if they are relevant. If you can determine the position of your subscribers during the customer process, you can send them an email with a corresponding question in the subject line.

If you answer the question later in the e-mail, you can kill two birds with one stone: subscribers are inclined to open the e-mail and if the answer meets their needs, they go further into the funnel.

7. Be creative

Think outside the box. Try something outside of your comfort zone and surprise your subscribers. A small joke , a clever play on words or something inventive that your readers might not expect. Everything that could attract attention in their inbox.

To use wisely, and only if you feel that your target group is open to it.

8. Make it personal

Email personalisation increases your opening ratios. Personalisation goes much further than inserting a name in your subject line or body copy. But it’s definitely a start. Addressing someone directly is an effective way to get someone’s attention, both in real life and in the inbox.

9. Make your reader feel special

Everyone wants to be part of the ‘inner circle’. And the subject line is an ideal opportunity to meet that need. By giving your subscribers a sense of belonging, you can build a loyal relationship, so that your subscribers can open your e-mails.

Using “you” and “your” help the reader to relate. It’s a psychological thing: exclusivity works.

10. CAPS, question and exclamation marks

Spam filters search for certain criteria in emails that ensure that your email is categorised as spam. Some of these criteria apply to the subject line. IF YOUR SUBJECT LINE IS WRITTEN IN CAPS, it will often be seen as spam. Plus, nobody likes shouting.

Another important criterion is punctuation. An exclamation mark can certainly give some extra power to the subject line, provided you limit it to one. Using multiple exclamation marks can also land your email in the junk folder.