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How to write great email subject lines

Want to maximize the chances of your emails being opened? Read this article to find out how writing great subject lines can help.

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    By James

    James has six years' experience as a Content Marketer, bylines on Left Foot Forward, Submittable, and INOMICS, and a Master's in History. In his free time he likes to read, play guitar, and write for his personal blog.

    Despite the myriad marketing approaches available today, email marketing is still ever-popular.

    It can be especially efficient if you spend time researching the best way to implement this strategy correctly - with the right recipe in hand, you can end up with great results.

    The subject line of an email is important because it’s one of the first things people see. It comes before witty taglines, attractive pictures, or enticing offers.

    This means that if it’s not appealing enough, the email won’t even be opened.

    All the effort that you'll have poured into crafting the most impactful content will have been wasted.

    For this reason, getting your email subject line right is crucial. But how?

    It can seem like a near-impossible objective to reach, given the sheer number of emails an average person can receive in a day.

    If you’re not sure about how to develop great email subject lines, this article is for you.

    The following sections first briefly cover what email marketing is, and then delve into the details of what subject lines are, why they’re important, and the steps that you can take to make them irresistible.

    What is email marketing and is it important?

    Though many have embraced face-to-face communication systems such as the Microsoft Teams app, email is far from obsolete.

    In 2020, global email users amounted to 4 billion and this number is set to grow to 4.6 billion users in 2025.

    This statistic alone is enough to illustrate how email marketing can be a great strategy.

    In essence, email marketing is a powerful marketing channel, which uses email to promote a business’s products, services, and inventory management software capabilities.

    It’s a great way to share information about sales, promotions, and general updates, all the while building a relationship with your customers. To get a better idea, take a look at this example of email marketing by Amazon Prime:

    Example of email marketing by Amazon Prime

    Email marketing can be a great way to advertise your products, acquire new leads, and turn existing leads into customers, as the example by Amazon Prime demonstrates.

    The benefits of email marketing include the following:

    • Great way to deliver targeted and tailored content 
    • Inexpensive 
    • Time-efficient
    • Easy to implement, especially combined with automation tools 
    • A flexible approach that can easily grow with your business 
    • Measurable

    Given these advantages, it's easy to see why so many businesses opt for email marketing. But as mentioned, great content is only going to be seen if your recipient opens your email.

    Does the subject line matter?

    In short, yes.

    Before we get into the why, here’s what a subject line is: 

    Screenshot highlighting the subject line of an email

    As you can see from the image above, the subject line is the text that a recipient sees next to the title in their email inbox.

    The subject line has a direct effect on email open rates, which is given as a percentage. This useful metric immediately tells you whether your title and subject lines are working or not.

    According to research, the average American has 1,602 unread emails in their personal inbox.

    That’s why it’s so important that your subject line stands out from the crowd so your prospects won’t just scroll past or hit the delete button.

    It might be tempting to take the spaghetti on the wall approach in the hope that something will stick.

    In fact, bombarding the prospects on your email list with hundreds of emails is counterproductive. 

    It’s also best to avoid spammy subject lines that will just end up in your recipients’ spam folders.

    When it comes to email subject lines, quality trumps quantity and spammy tropes every time.

    Taking the time to craft witty or intriguing subject lines will definitely pay dividends.

    Read on to discover some great ways to formulate effective subject lines and increase your email open rate.

    8 tips on how to write great email subject lines

    Keep it short and catchy

    Example of a short and catchy email subject line

    In today’s fast-paced world, your customers don’t always have the time to read long titles and subject lines carefully.

    They often make snap judgments about whether an email is worth opening and spending time on. 

    Recommended reading: How to start an email

    One of the best ways to tip this in your favor is to keep your subject lines short, sweet, and catchy.

    Take the example above: the subject line “Make a splash this summer” is just that. It doesn’t take long to read, it’s easy to understand, and it sounds good.

    What’s more, keeping it short ensures that your subject line doesn’t get cut off and that you convey your message straight away.

    Make it personal

    Another way to get your recipients to read your emails is to personalize your subject line to let your prospects know that you see them as an individual rather than a nondescript part of a group of consumers.

    You can also do this by referencing a past purchase they have made with you. 

    In addition, segmenting your recipients can help you ensure that the emails you send are as relevant as possible to those who receive them.

    Foster a sense of urgency (when appropriate)

    No one likes to feel like they are missing out, whether on a great experience or a good deal. 

    Craft a subject line that conveys a sense of urgency to encourage your recipients to take action.

    The mention of a time-limited offer or rapidly decreasing stock is more likely to drive your customers to take action so that they don’t miss out.

    It goes without saying that you should only do this in genuine cases, that is to say, don't claim that an offer is limited when it isn’t just to foster interest. This could backfire on your brand and damage your reputation. 

    Avoid spammy language

    The last thing any business wants is to invest time and resources into a great marketing strategy only for the emails to land in its clients’ spam folders.

    One of the best ways to avoid having your customer service email ignored is to ensure the language you use in your subject line is not too aggressive.

    Below is an example of what a spammy subject line looks like.

    Example of spammy email subject line


    Pushing a sales pitch too hard and using overly excited language and punctuation will likely land you in the spam folder.

    This is why a subject line like “CLICK THIS EMAIL TO GET 15% OFF!!!!!!” or “You are TODAY’S WINNER” is not going to get you anywhere.

    All caps and too many exclamation points are a big no in email marketing.

    Grab attention

    It goes without saying that your subject line needs to grab the customer’s attention so that your email stands out from the sea of other emails that are asking to be opened.

    “Know thy prospect” is a well-worn mantra for good reason.

    If you know your prospects’ interests and pain points, it’s easier to engineer a subject line that will grab their attention.

    If you know they’ve already shown an interest in product innovations, training courses, or industry events, you can use this information to your advantage.

    The language you use and the key message should also be carefully thought out and tailored to your audience.

    Ask yourself the following questions:

    • Would my prospects respond well to humor, such as puns and another wordplay? 
    • Would including age-, gender-, interest- or industry-specific jargon be off-putting or engaging for my prospects? 
    • Could I highlight an enticing promise that will be fulfilled in the email body e.g. a discount code or free content?
    • Could the subject line include something genuinely newsworthy that will spark curiosity?

    Use questions

    Another useful tip is to feature open-ended questions in your subject lines. This is more likely to retain your clients’ attention than a statement (be it for a few seconds) as they think of an answer.

    What’s more, the question might be relevant to them or even something that they recently asked themselves. Whichever it is, it increases the chance of them clicking on your email.

    Generate your subjects lines with help from AI

    Writing out lists of subject lines for your emails can take up a lot of time, and getting them right is difficult! You can make things easier for yourself, though, by using artificial intelligence to automatically generate lists of subject lines, meaning you don't have to write them all out yourself.

    AI programs can automatically compose subject lines for you based on just a few keywords. They can even then compose the whole message for you if you need them to. If you enter a few more input words, you can generate full lists of subject lines that you can use for various different emails, saving you tons of time and effort.

    Hint to valuable content

    If you’ve got great content that you know will be useful to your client list, why not make this evident from the get-go?

    Providing consumers with a solution to a problem is a great way to engage them and encourage interest in the products or services you offer. 

    It’s important to consider the best ways to maximize the impact of particular upcoming events or deals.

    For example, a Black Friday email subject line should grab your audience's attention and suggest that great deals are to be had if you read on.

    Use this to your advantage and hint at a solution in your subject line!

    For instance, an individual looking for a system that provides unified communications will waste no time opening an email if the subject line mentions the Microsoft direct routing feature.

    Use trends to stay relevant

    Finally, make use of trends. This will allow you to craft subject lines (and email content) that not only are relevant to your audience but also appeal to younger generations.

    It’s also a great way to keep your brand relevant and establish yourself as a business that is in the know or even a thought leader. Twitter can be a big help here.

    Using Twitter to research consumer trends


    How long should email subject lines be?

    On average, try to keep your subject line around 40 characters long. Keeping it short ensures that it can be viewed fully and that you can convey your message straight away.

    What are the two purposes of good email subject lines?

    The first purpose is that they catch your recipients’ eye and interest. The second is that they encourage clients to open the email.

    Can you use emojis in email subject lines?

    Sure! Providing they’re in keeping with your brand image, they can make subject lines very eye-catching.

    Wrapping up

    An email marketing campaign can only succeed if your prospects actually open the emails you’ve sent.

    Creating great subject lines is one way to ensure they do.

    Some creativity paired with the eight tips shared in this article will get you writing winning subject lines.

    Remember: speak to your recipients’ interests based on the knowledge you have about them, don’t be afraid to personalize, and share your great offers. Happy writing!

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