50 Best Subject Lines for Emails: A Guide to Raising Open Rates

Alaina Bradenburger
Kassidy Vavra
Published: Dec 21, 2021
Last Updated:
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With new digital marketing channels like SMS, social media, and conversational marketing emerging each year, you may be tempted to ditch your email marketing campaign. But email is still one of the most efficient and cost-effective marketing channels. In 2020, email marketing generated $7.5 billion. For every $1 spent on email, businesses receive about $38 in return.  To help kickstart your campaign, we've provided a list of the 50 best subject lines for emails.

person holding phone next to laptop

Why You Should Still Be Sending Marketing Emails

Email campaigns allow you to reach potential customers on their own time. It’s also a great way to promote additional content and other marketing efforts, including promotions and sales. Sending a quick email with a link to your blog or social media helps drive customer engagement.

The email's subject line in email marketing is crucial to higher open rates and engagement. Using the right subject line can communicate the value of your newsletter to a potential reader and reduce your chances of being sent directly to the trash bin. In 2021, marketing emails had an average open rate of about 17% overall. To achieve higher open rates, your email content should provide value to the reader.

Here are some of the best subject lines for emails and best practices to keep in mind when crafting them.

Best Email Subject Line Examples

No single subject line works for every industry — or every email — but there are some ways to structure your email subject lines to make them stand out and improve your open rates. These tips and email subject lines examples are an excellent place to start creating your messages.

Ask a Question

Questions let you connect with the reader, and it gives them a glimpse into the email without giving it all away in the subject line. You can use questions to intrigue readers or frame your email as a solution to one of their problems. Many professional email subject lines aren’t phrased as questions, so these can help you stand out. Examples of email subject lines phrased as questions include:

  • Is your car ready for winter weather?
  • Have you taken advantage of 40% off?
  • What do customers think of your business?
  • Are you guilty of these web design errors?
  • Did somebody say "holiday savings?"

Create FOMO

The fear of missing out (FOMO) is a real phenomenon, which has been put into overdrive by social media. Nearly 70% of Millennials have experienced FOMO. You can capitalize on this by creating a sense of FOMO with your email subject lines. These subject lines work because they create a sense of urgency, prompting customers to act.

  • This sale ends in 12 hours.
  • Uh-oh, your loyalty points expire in 30 days!
  • Last chance! Save an additional 20% on sale merch.
  • Earn double miles on all purchases this weekend only.
  • We only have a few tickets left!

Be Funny

A catchy email subject line featuring puns or other funny language stands out among the crowd. The idea might seem a little corny at first, but these subject lines are a way to cut through the noise and intrigue customers. If your usual brand voice is light and airy, using a humorous subject line could be what you need to improve your open rates. Keep it light, don’t be offensive — and don't deter from your branding. If your tone (or subject matter) is usually more serious, you should probably avoid a funny email subject line.

  • A dog’s life can be ruff.
  • Sneak into our shoe sale for your new kicks.
  • Did you mean to ghost us?
  • You donut want to miss our grand opening.
  • Because putting on your game face takes too long

Showcase Your Value

Customers are more likely to open emails that benefit them. Use your subject lines to highlight how the email will help them. These subject lines are ideal for email links to products or services that simplify a customer’s daily responsibilities. If you’re sending a link to a product demonstration video or a link to customizable templates, these subject lines can entice your readers to open the message. Be honest. Don’t over-promise if you can’t deliver.

  • How to improve your marketing reach in 30 days
  • Dinner prep used to take hours until I found [product].
  • Don’t waste brain cells on [task] — use this template instead.
  • X tips for writing business proposals that get you hired
  • Register for our new investment strategies webinar.
  • X blog post ideas for the new year
  • Your complete guide to selling
  • How to [your service]
  • The best ways to [your industry or service]
  • How to find the best hotel deals in every city

Appeal to Your Readers’ Vanity

Although most people wouldn’t likely classify themselves as vain, acceptance is a common emotional need. If you are selling a product or service that helps meet this need, use email subject lines that appeal to this emotion.

  • Because straight-legged jeans are the new skinny jean
  • Show everyone on Facebook how much you’ve changed.
  • Save now on our best sellers!
  • Skip the lines! Register now for VIP entry.
  • Look fresh-faced even after pulling an all-nighter.

Connect to Your Readers

One of the best ways to improve open rates is to be personable and cultivate a relationship with your customers. Today’s customers expect personalized content, which includes email marketing. Sending a personalized email can improve your customer transactions by six times.

  • Happy birthday!
  • Thank you for being a loyal customer.
  • [First Name] you’ve reached gold-star status.
  • [First Name] Welcome to our mailing list!
  • Take another look.
  • Come back and finish shopping.
  • Forget something?
  • [First Name], good news! The item in your cart is on sale.
  • Thank you for your support this year.
  • You asked, and we listened.

Pique Their Interest

Creating somewhat vague yet intriguing subject lines can garner interest in your email. Write subject lines that make people curious enough to open your email, but don't give away the subject matter inside. These email subject lines are great for cold emails and other messages that offer new and valuable information for your readers.

  • What is the hottest zip code in the United States?
  • Why you should stay home on Black Friday
  • Coming soon…
  • Guess what?
  • Bizarre hacks for making the most of your side hustle
  • When was your last vacation?
  • We’re unveiling something new.
  • Unexplored tricks for [subject of interest]
  • Behind the scenes at our manufacturing plant
  • Secrets for getting more website traffic revealed

How to Write a Good Subject Line in an Email

Even if you’re not a copywriter who can instantly come up with subject lines, knowing some basic rules can help you improve your open rates. Poorly written subject lines can land you in the spam filter, so keep these tricks in mind.

Keep It Short Yet Detailed

Since people receive so many emails every day, they are likely to scan subject lines to determine which to open and delete. Short subject lines are generally more effective. Additionally, shorter subject lines are better for mobile devices since longer ones can get cut out. Nearly half (42%) of users will open emails on their phones or other mobile devices.

If you tend to get wordy in your subject lines, keep rereading them and remove unimportant words. Find places where you can use succinct language to convey the same idea and inspire action. For example, instead of saying, "This item only goes on sale once a year," you could say, "Take advantage of our once yearly sale on [item]." While both subject lines have the same amount of words, the second is more detailed and includes a call to action.

Avoid Spam Triggers

Many spam filters identify common words that signal fraud and malicious intent. Unfortunately, many of these flagged terms are also used in everyday language. Avoiding common spam triggers in your subject lines will help you stay out of the junk filter and on the safe list. Some words on the spam trigger list include:

  • Discount
  • Eliminate debt
  • Act now
  • No hidden fees
  • Pre-approved

These and other phrases are often found on malicious emails, so they tend to get filtered before your email arrives in a recipient’s inbox. Check the list for commonly flagged phrases and rework them so they don’t include trigger words.

Create a Sense of Urgency

If your email subject line contains an expiration date, it can prompt people to open the message. Many people don’t want to miss out on a good deal, so adding limits in the subject line communicates that your offer is limited.

You can also create urgency by letting a customer know that time is running out. This is a good marketing strategy for abandoned cart emails. You can automate an email that tells a shopper that inventory is limited, so they should come back and complete their purchase.

Keep It Timely

People generally like email newsletters that are timely and relevant. Linking your email to the latest trends, current events, and developments in your industry can help improve your credibility. Likewise, sending out emails with links to outdated information can make it seem like you aren’t keeping up with your competitors.

For example, when the COVID-19 pandemic forced businesses worldwide to shut down, many companies sent out emails with subject lines offering words of comfort. Many also used emails to communicate what they were doing to keep employees and customers safe.

While you may not have to tailor your email subject lines to a once-in-a-lifetime newsworthy event, there are likely hot trends and topics in your industry that can impact your customers. Addressing these in your email marketing is an excellent way to improve open rates.

Add a Call to Action

Calls to action (CTAs) create a sense of urgency and alert your reader to act fast. Be creative with your calls to action, so you can stand out and avoid getting flagged as spam. If you’re promoting an upcoming webinar, include a simple CTA like “Join Us” to entice readers to sign up.

You can personalize your calls to action by using language like “Try [business name] for a limited time.” Or include the email recipient’s first name to appeal directly to them. Most email management programs have features that let you personalize your subject lines by automatically populating them with the recipient’s name.

Make It Seasonal

Another way to create timely subject lines is to write seasonal emails and reference them in your subject lines. This is a common practice for retailers announcing sales and other promotions for different seasons. You’ve probably gotten plenty of Black Friday promotions or New Year’s Eve party outfit suggestions in your inbox.

Even if you’re not a retailer, you can still personalize your sales emails. For example, if you’re selling insurance, you could send out an email with the subject line, “10 tips for winterizing your home.” If you’re running a small bakery, you could send out a weekly newsletter, reminding people that Valentine's Day is near.

Write Multiple Subject Lines

Mastering sales email subject lines takes some practice. Even professional copywriters will often write multiple subject lines for the same email to see what works and what doesn’t. Draft a couple of subject lines and read them aloud to see how they might sound to your customers.

When you’ve picked your favorite, reread it a few times to see if you can shorten or simplify it. When starting, test different subject lines against each other by sending out the same email to different sections of your email list, changing the subject of each. You will eventually get an idea of which promotional emails are the most effective.

How to Write the Best Subject Lines for Emails

Writing the subject line is often one of the most challenging parts of sending marketing emails. What works in some industries might fall flat in others. But having an idea of best practices and compelling subject line ideas gives you a place to start.

When writing your next email marketing message, consider which type of subject line is best for your message and experiment with different styles. Eventually, you will master writing subject lines that get noticed.

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