18 Secrets to Boost Your Email Open Rates

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It doesn’t matter how great your email content is if nobody opens it.

You’ve got just three seconds.

That’s the time you have to grab attention in a crowded inbox. With billions of emails sent daily and the average person getting around 120 emails a day, your subject line is your best shot at standing out.

If it misses the mark, all your effort goes to waste. But don’t worry. In this newsletter, I’ll guide you through 18 proven strategies to create subject lines that get results. Let’s get started.

18 Email Subject Line Best Practices to Boost Your Open Rates

Crafting the perfect subject line can make a big difference. It often determines whether your email gets opened or ignored. Here’s how to create subject lines that grab attention and drive engagement:

1. Make Your “From” Field Count

While it’s not technically part of the subject line, the From field is crucial. A surprising 55% of people decide whether to open an email based on who it’s from.

Even major companies sometimes get this wrong. To avoid being mistaken for spam, ensure the From field clearly identifies who the email is from. Testing variations like using the company name versus a personal email address is okay, but keep it consistently recognizable.

Example:

• Good: [email protected]

• Less effective: [email protected]

Consistency in the From field helps build trust and ensures your emails aren’t overlooked.

2. Keep the Length to 50 Characters (Including Spaces) or Less

With half of email users checking their messages on mobile devices, keeping your subject line short is essential.

On mobile, notifications typically show up to 43 characters, and apps display up to 53 characters. If your subject line needs to be longer, make sure to place the most important information at the beginning or in the preview text.

Example:

• Good: “Unlock Your 20% Discount Now!”

• Less effective: “Here’s Your Exclusive 20% Discount on Your Next Purchase – Don’t Miss Out!”

By placing key details at the beginning of your subject line, you ensure that your message stands out even when viewed on a mobile device. Take a look at the example below.

Desktop vs. Mobile

3. Match Your Tone and Level of Formality to Your Brand

Your subject line should reflect your brand’s tone and formality. Whether your brand is casual and fun or serious and formal, it should resonate with your audience.

B2B communications generally lean towards a more formal tone, while B2C tends to be more relaxed. Test different tones to see what resonates best with your readers.

4. Use sentence case for your subject lines

Using sentence case is generally the most effective approach. You can use capitalization for emphasis, but don’t overdo it.

Avoid using all caps—this can come off as shouting. Title case can make your email look too formal and businesslike. Experiment with lowercase if it aligns with your brand’s voice and feels more personal.

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5. Be Descriptive

Sometimes, clear and direct is better than trendy. Rather than using vague slogans like “Fall into savings” or “Sizzling summer bargains,” be specific about what your email offers.

Focus on communicating the benefits of your promotions or highlighting specific deals. This approach provides a clearer hook and makes your subject line more compelling.

6. Limit Punctuation

Using too many punctuation marks can make your email look spammy. Stick to a maximum of 3 punctuation marks per subject line to maintain a professional appearance.

7. Use Emojis Carefully

Emojis should enhance, not distract. Use them to highlight important details or add a touch of personality.

For example, if you’re sharing a special offer, a gift emoji 🎁 can catch attention. However, overusing emojis can make your message seem less serious. Balance is key!

8. Personalise Your Subject Lines

Personalisation isn’t just for subject lines, but let’s start there. Using your reader’s name, like ‘Hey, Bob,’ instead of ‘Dear Sir or Madam,’ really makes a difference.

In fact, it can boost open rates by 26%! It’s a quick, friendly touch that makes your emails stand out and feel more personal.

9. Ensure Email Content Matches Your Subject Line

Ensure your email content matches your subject line. If your readers click expecting one thing but get something entirely different, they might stop opening your emails.

For example, if your subject line promises “Exclusive Tips Inside!” but the email only contains hype and a vague link, readers will feel misled.

Keep it honest and relevant to build trust and keep your audience engaged.

10. Use AI for Subject Line Inspiration

Coming up with engaging subject lines can be a challenge. Let Wiiv.AI make it easier. Subject lines are essential for grabbing attention, and Wiiv.AI’s AI technology helps you create compelling, click-worthy options tailored to your audience.

By analyzing past data, Wiiv.AI ensures your subject lines boost open rates and drive meaningful engagement, so your emails stand out and prompt action.

11. Sneak a Joke Into Your Subject Lines

Adding humor to your email subject lines can make them pop and grab attention. A funny line can make your readers smile and boost opens.

Just make sure your joke resonates with your audience—humor works best when your recipients get the joke!

12. Reveal Discounts and Freebies in Your Subject Lines

Everyone loves a good deal or a freebie! If you're offering something for free, make sure to mention it right in the subject line. Emails that highlight free gifts or discounts upfront tend to have much higher open rates.

It’s a simple yet effective way to grab attention and get more eyes on your offers.

13. Use Numbers and Lists

Numbers and lists grab attention and simplify your email content. In fact, data shows that emails with numbers in the subject line have a 24.97% open rate compared to 23.34% for those without.

Use numbers to highlight key points or steps, and organize information in lists to boost engagement and make your emails more compelling.

14. Make People Feel Special

The psychology of exclusivity works wonders. When people feel they're part of an exclusive group, it fosters a sense of belonging and encourages them to act on your emails.

Use the right phrasing to make your recipients feel special. Consider phrases like:

• “For our beloved customers only…”

• “An exclusive offer for you…”

• “My gift to you…”

• “You’re invited!”

• “Private invite…”

These can create a magical effect, boosting engagement and loyalty.

15. Keep It Real

Skip the spammy, clickbait phrases and don’t overdo the exclamation points or CAPS. Readers can spot gimmicks a mile away. Stick to a clear, honest subject line to keep your emails from being flagged as spam.

16. Using Social Proof in Email Subject Lines

Social proof is a powerful tactic for enhancing engagement and credibility in your emails. It relies on the idea that if others find something valuable, you’re more likely to see its worth too.

Show impressive numbers with subject lines like “Join 10,000+ happy customers” or “See why 98% of users recommend us.”

Combine social proof with curiosity by using lines such as “Why top industry leaders are raving about our new feature” or “Find out what 5-star reviewers are saying about us.”

17. Segment Your List

Personalization also means sending the right message to the right people. Segment your email list by demographics, behavior, interests, or sign-up date to tailor your subject lines. This approach improves engagement and conversion rates.

18. Test, Test, and Test Again

Testing is crucial for determining what works. Use A/B testing to compare different subject lines and see which ones perform best. This technique isn’t limited to subject lines; you can test preheaders, email content, and sender addresses too. Just ensure you test one element at a time for clear results.

By using these subject line strategies, you’ll be well on your way to more opens and higher engagement. Which tip are you most excited to try? Hit 'reply' and let me know—I’d love to hear from you! Until next time, keep testing, learning, and growing. 🚀