Email Subject Lines That Work: 10 Do’s and Don’ts

By Debbie Dawson, Senior Account Director

I am asked routinely by our clients for email marketing best practices and, specifically, about B2C subject lines. According to DataMentors, an email has only 3 seconds to capture a reader’s attention. A strong subject line could mean the difference between an email being opened or deleted, making it an integral component of email marketing success.

Here are my top takeaways on crafting email subject lines that work:


1. Keep it Short – While there are differences in opinion on this topic, most research comes out in favor of shorter subject lines (50 or less characters) due in part to the increased use of mobile devices. However, Email Audience cited that “emails over 80 characters, especially those in the 100 character range, perform best” and reported a 115% increase in B2C open rates, and an 85% increase in click-thru rates with 20 word subject lines over emails with shorter subject lines. We recommend keeping it short and simple.

2. Keep it Simple and Relevant – MailChimp’s research shows that plain and descriptive subject lines fare much better than overtly sales-driven, cute, or promotional ones. Don’t try to trick people into reading your email. Your subject line should clearly outline what is inside the email. If you are sending a newsletter, your subject line should include the word “Newsletter”. MailChimp also recommends adding your company’s name to the subject line.

3. Make it Personal – Add a personal touch and add your customer’s first name to the subject line. Experian recently reported that including the recipient’s name in the email subject line increased open rates in almost every industry studied some by as much as 42%. Incredibly, research has shown that only 35% of marketers are using personalization in their subject lines. It is easy to put it to the test as most email providers enable you to insert a recipient’s first name simply by inserting a custom field into the subject line. Test it!

4. Incorporate Emojis – According to research conducted by Experian CheetahMail, subject lines with emojis reported a 56% lift in unique open rate. The most popular emojis seen in subject lines in order of popularity are:

♥ ★ ☼ ♫ ☀ ✿ ☆ ♡ ⇒ ☺ ❤ ✈ ✞ → ☂

Interestingly, the black heart is the most popular but provided only a 2.2% unique open rate lift, while the airplane had a 10.7% rate lift and the umbrella generated a 50% lift.

Bottom Line:

Caution: Not all email clients will display emojis correctly, so it is always a good idea to test this internally before deploying to the masses and have a back-up plan for platforms that won’t display them. For more on emojis, check out our blog post: 6 Ways Your Brand Can Use Emojis in Marketing.

5.  Test & Optimize – Always be testing (subject line length, use of emojis, personalization, etc.). Your audience is one of a kind and might react differently. And, if your email client has an A/B testing feature, use this functionality to refine your subject lines and email content.


1. Avoid Triggering Spam Filters – Avoid the use of spammy phrases like “free”, “now”, “cash”, “percent off”.

2. Don’t Use ALL CAPS – They stand out for the wrong reasons.

3. Avoid Excessive Punctuation – Exclamation points in particular are noisy, send the wrong message and may trigger spam filters

4.  Don’t Oversell or Be Deceptive – Consumers are already on high alert for gimmicky sales emails, so don’t try to trick them into reading yours or it could back fire.

5. Don’t Insert “Fwd:” or “Re:” – This creates serious mistrust and could turn your customer off for life.

Like headlines, a subject line needs to succinctly summarize the message that you are trying to convey. Keep in mind, 80% or more of the folks receiving your email will likely read your subject line but only a small fraction of those will feel compelled enough to open your email. The key is to create a subject line that is simultaneously captivating and sincere.

More resources to improve your email marketing:

Make Your Emails Delete Proof
Doesn’t it kill you? You spend hours…days…crafting a brilliant piece of email marketing, and as soon as it’s sent, a huge proportion of your recipients delete it…UNREAD.

Free Guide: Email Marketing KPIs You Might Be Overlooking
Email is an essential marketing channel for brands around the world. But, which email marketing key performance indicators (KPIs) really matter and why? Beyond the basics, we dug a bit deeper to look for the KPIs that are not as often measured, but just as critical.

Debbie Dawson

Debbie Dawson

Senior Account Director at Eclipse Marketing Services
Debbie has over 20 years of award-winning consumer marketing experience. She loves the challenge of determining what motivates consumers and creating marketing campaigns that solve problems in creative ways. Follow Debbie on LinkedIn
Debbie Dawson

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2 thoughts on “Email Subject Lines That Work: 10 Do’s and Don’ts

  1. I’ve never seen a person’s name in the subject line. That doesn’t strike me as something I would like to see. I would think it was spam or something. But I did enjoy reading your article.

  2. Great tips Debbie! I didn’t make any use of emojis in subject lines before even I have never thought of this way but if there are researches, I would surely try this thing out. Thanks for sharing.

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