March 6, 2020 · Richard Prime
How to write better email subject lines
Your subject line is the first thing people see when your email lands in their inbox. It is also, more often than not, the thing that decides whether they open it or scroll past. You can spend hours crafting the perfect email, but if the subject line does not grab attention, none of that effort matters.
The good news is that writing better subject lines is not complicated. It just takes some awareness of what works and what does not. Here are the principles we have found most effective.
Keep it short and specific
The best subject lines are usually between six and eight words. That might feel limiting, but it forces you to get to the point. Long subject lines get cut off on mobile devices, and most people scan their inbox quickly. You have about two seconds to make an impression.
Instead of writing “We are excited to announce our brand new summer collection for 2020,” try something like “Our summer collection is here.” It says the same thing in fewer words, and it is much easier to process at a glance.
Why brevity matters
People receive dozens of emails every day. A short, clear subject line respects their time and stands out against the clutter. It also shows confidence. You know what your email is about, and you can communicate it without rambling.
Avoid generic greetings
Subject lines like “Hello from us!” or “Just checking in” tell the reader nothing about what is inside the email. They feel impersonal and forgettable. Even worse, they can look like spam.
Instead, lead with the value. What is the reader going to get from opening this email? A useful tip? A special offer? An important update? Make that clear right away.
Skip this: “Hey there, we have some news” Try this: “Three new templates you can use today”
The second version tells the reader exactly what to expect and gives them a reason to click.
Convey importance without alarming
There is a fine line between creating urgency and sounding like a fire alarm. Subject lines like “URGENT: Act now before it is too late” feel manipulative and erode trust over time. People learn to ignore them.
A better approach is to suggest importance through specificity and timeliness. “Registration closes Friday” is urgent without being aggressive. “Your annual report is ready” implies importance without shouting.
The goal is to make people feel like they would miss out on something useful, not scare them into opening the email.
Never use ALL CAPS
Writing your subject line in all capital letters is the digital equivalent of shouting. It looks aggressive, it looks unprofessional, and most email clients will flag it as potential spam.
If you need emphasis, use it sparingly and through word choice rather than formatting. A well-written subject line does not need to shout to be noticed.
Ask a question
Questions make great subject lines because they naturally invite engagement. When someone reads a question, their brain automatically starts thinking about the answer. That moment of thought is often enough to get them to open the email.
“Are you making these common email mistakes?” works because it creates curiosity without being clickbaity. “What is the best time to send your newsletter?” works because it promises useful information.
The key is to ask questions that are genuinely relevant to your audience. Do not ask questions just for the sake of it. If the question connects to what is inside the email, even better.
If you are curious about timing, by the way, we have a guide on the best time to send newsletters that covers this topic in depth.
Make it personal, but not creepy
Personalization can boost open rates, but it needs to feel natural. Using someone’s first name in the subject line can work well, but only if it fits the tone of your email. “Sarah, your order has shipped” feels appropriate. “Sarah, we have been watching your activity” does not.
The best personalization comes from knowing your audience and writing subject lines that feel like they were meant for them specifically.
Avoid spam trigger words
Certain words and phrases are more likely to get your email caught by spam filters or ignored by readers. Words like “free,” “guarantee,” “no obligation,” and “act now” have been overused to the point where they signal low-quality content.
That does not mean you can never use them, but be aware that they carry baggage. If your subject line reads like a late-night infomercial, it is probably worth reworking.
Bonus tips
Here are a few additional tricks that can give your subject lines an edge:
Include the word “newsletter”
If you are sending a newsletter, saying so in the subject line sets clear expectations. People who signed up for your newsletter want to receive it, and seeing the word helps them recognize it in a crowded inbox. Something like “March newsletter: tips for spring campaigns” works well.
Add your company name
Including your company or brand name in the subject line builds recognition over time. It helps readers quickly identify who the email is from, especially if your “from” name is a person’s name rather than a brand name.
Use numbers and dates
Numbers catch the eye. “5 ways to improve your open rates” is more compelling than “Ways to improve your open rates.” Dates and timeframes also add specificity. “This week only: new features available” gives readers a concrete sense of timing.
Test and learn
The truth is, what works for one audience might not work for another. The best way to improve your subject lines over time is to pay attention to your open rates and experiment.
Try different approaches. Compare short subject lines with slightly longer ones. Test questions against statements. See whether numbers make a difference. Over time, you will develop a sense for what resonates with your specific audience.
If you want to learn more about crafting emails that work, check out our guide on how to create engaging emails for small business marketing. And if you are still building your email list, our post on how to start a newsletter covers the fundamentals.
A quick checklist
Before you hit send, run your subject line through this quick check:
- Is it six to eight words or fewer?
- Does it tell the reader what is inside?
- Would you open an email with this subject line?
- Is it free of all caps, excessive punctuation, and spammy language?
- Does it create curiosity or offer clear value?
If you can answer yes to all five, you are in good shape. Happy sending.