HomeEmail Marketing13 Tips for Writing Email Subject Lines

    13 Tips for Writing Email Subject Lines


    I would say that email subject lines are possibly the most important factor when it comes to email marketing. After all, if you can’t get a subscriber to click your email, nothing else matters. You see, the subject line is key for making your email stand out and getting them to click, increasing your open rates. But it can be challenging to perfect an email subject line, whether you work in marketing or not, as every audience is different. These tips for writing email subject lines will help you improve, and they act as a guide, not a compulsory checklist!

    What Is An Email Subject Line?

    An email subject line is the text you see in your inbox, before opening an email. This text is set by the email sender and is the main factor that determines open rates.

    What Is An Email Pre-Header?

    An email pre-header is the text that comes after the subject line, often a preview of the content within the email. The pre-header is technically still considered as the subject line as it appears in the same place.

    The email sender is able to define the pre-header before sending, however, if nothing is set, sometimes the pre-header will auto-populate with the first line of text from the email. The pre-header is another opportunity to encourage users to open the email.

    Let’s get into the 13 tips for writing email subject lines:

    Ask A Question

    Asking a question is a great opportunity to spark curiosity and interest amongst your subscribers. Stating the obvious be sure not to put the answer to that question in the subject line too – as that will defeat the point. Asking an intriguing or ambiguous question will push the subscriber to click the email and find the answer.

    One of the most popular questions is ‘Did you forget something?’ This is usually sent by e-commerce stores or websites that are selling a product/service. This question actually makes the subscriber believe they have missed something, encouraging them to go back and check what they missed. Commonly, it is followed with a discount code in the email body to encourage them further.

    If you use questions in your subject line outside of e-commerce, I would recommend using them sparingly. Too many of these will lessen the effect.

    Keep It Short & Concise

    Writing an email subject line that’s short and to the point is essential. Not only do lengthy subject lines become boring and cause readers to lose interest, but they also don’t show correctly on mobile devices. After all, you have the main email body to put lengthy information – this doesn’t need to be crammed into a subject line. The goal of any email subject line is to get the user to open the email – not to tell a story.

    Take a look at this example from Tripadvisor, it’s short, has a CTA, provides information, and creates a sense of urgency with the use of 13 words:

    Whereas this example (I won’t name the company) is a mess. The subject line itself is ‘ok’ but it’s not strong and it doesn’t really stay concise. Then the pre-header text extends this with nonsense. The text doesn’t actually end until it’s forced to cut off (it’s likely they didn’t set a pre-header so it was pulled from the email body copy.).

    When users have to scroll through 60+ emails, they aren’t going to pay attention to the lengthy ones unless there is something unique in the middle to grab their attention. In the example below, I wouldn’t waste my time reading the longer – plain text subject lines and pre-headers.

    Use Emojis When It’s Right

    Emojis are a part of everyday life, whether it’s professionally or personally, they are embedded into modern-day communication. And with email marketing, they can be incredibly powerful. For example, a study by NetHunt revealed that emails with emojis included in the subject line have open rates that are 56% higher compared to subject lines with no emojis.

    For example, in the bunch of emails below, which subject lines stand out instantly? Our eyes are drawn to the emojis because they differentiate from the wall of text.

    However, the use of emojis has its time and place. If you go down the route of using an emojis in the subject line, be sure to consider the following:

    • They align with your brand.
    • You understand their meaning, and meanings can change with current trends (especially cross-culturally).
    • You check they display correctly on different devices/models.
    • Your audience demographic can resonate with emojis.
    • You don’t use them incorrectly (such as posting an emoji linked to a sensitive topic).

    Avoid Spam

    Being flagged as spam can be detrimental to your email marketing campaigns and it can impact your sender reputation, so you’ll want to take time preparing and checking your email to ensure this doesn’t happen. Of course, this also applies to your subject line. There are many factors that can trigger spam including, overuse of emojis, using trigger words repeatedly such as ‘free’, ‘guaranteed’, or ‘100%’, and even words to create urgency such as ‘apply now!’.

    Many triggers can land your email in the spam folder, but that’s not to say you can never use them. If you want to advertise something that’s ‘free’ for example, that’s fine. Just don’t spam the word ‘FREE’ everywhere and send 5+ emails with the same subject line including ‘FREE’.

    Some other things to avoid:

    • Putting words or phrases in all CAPITAL LETTERS
    • Incompatible fonts or different styles
    • Overuse of punctuation marks (??????, !!!!!!, ?!?!?!?!?!)
    • Overuse of numbers and symbols ($$$, 1,000,000,000,000) 

    Add Personalization Where You Can

    According to HubSpot, the most effective subject lines are personalized, promotional, and engaging. With so much noise and competition in email inboxes, personalization is going to help you stand out. According to the latest email marketing statistics, 80% of customers are likely to purchase from a brand that includes personalized experiences in their emails. As a consumer myself, I appreciate emails more when they use my name or mention my interests, and so do most people.

    To add personalization to your email campaigns, you will need to be comfortable with using dynamic tags (tags that pull data such as {first-name}). If you get these tags wrong, it could be slightly embarrassing as you could end up addressing every user by the same name.

    With personalization becoming more advanced, thanks to AI, it’s now possible to go further and look into hyper-personalization. This uses real-time data to understand customers even deeper, allowing brands to personalize further.

    Although personalization is a key benefit of email marketing, I do, however, suggest that personalization is used sparingly. Subject lines should be different and unique, if you use someone’s name or location over and over, they will start to notice and just ignore your email – or you could potentially get moved to spam. If you need to, consider using email marketing platforms for beginners, which have features and support built-in.

    Don’t Mislead People

    This is arguably one of the most important tips for writing email subject lines, but it also applies to everything in marketing. If you create a subject line that says ‘opening this email will give you a free coffee’ for example, you better make sure you are giving users a free coffee (somehow) in your email body. If not, then you are misleading the user. In other words, don’t use clickbait in your subject lines unless you are following through on it.

    You might be able to get away with it once, but if you do it repeatedly, not only will you damage the trust that has been built with your audience – you will also risk losing them as subscribers completely. Not to mention that they will stop clicking your emails too, causing drops in open rates.

    Another misleading tactic is including ‘RE:’ at the start of your subject line. This tricks the subscriber into thinking they have already engaged in an email conversation, causing them to open it and find out what they said. When in fact, it’s a misleading marketing tactic – which some high-level brands still do – I don’t agree with this tactic though.

    Just be sure to avoid false promises, saying things you won’t follow up on, and any shady tactics to get people to open an email.

    Write The Subject Line LAST

    This might be a controversial email marketing tip as some marketers recommend writing the subject line first – however, I recommend writing it last. By writing the subject line last, you can communicate the body of the content authentically and accurately. The email body should inform the content of the subject line – not the other way around.

    Imagine you spend time crafting the perfect subject line. Then create the copy for the email, but you realize they don’t quite complement each other. You’re not going to re-write the body of the email, it’s going to be the subject line. The same applies if you are testing variations of subject lines – you need to make sure all of them resonate with the content inside your email.

    Include A Call-To-Action

    Who said that a call to action (CTA) should go at the end of content? When it comes to email marketing, consider the subject line as a separate entity where you have to encourage someone to take action (open your email), what better way to do that than with a CTA? It could be something as simple as ‘get your copy’, ‘RSVP’, or ‘book now’ – like the example below:

    It’s worth noting that according to Wordstream, emails with a single CTA can increase clicks by over 371% and sales by around 1617%. You should still include a CTA in the email body though, one CTA for getting readers to open the email, then another to get them to take the desired action you want.

    Everyone appreciates a little humor now and then, whether it’s a pun, silly emoji, or a joke. One of my top tips for writing email subject lines is to add humor. If you manage to convey the humor correctly, usually the audience will click on the email to read more. It is important, however, that you maintain that humorous tone in the email body, otherwise you could lose the reader at that point.

    The same applies to adding trending topics in the world to your subject lines, especially when 33% of users choose to open emails because of catchy subject lines. Anything that trends can usually pique the interest of readers, for example, AI was an extremely hot topic a year ago (it still kind of is), and almost every subject line contained the word AI. You should check the news and social media to see what’s trending and try to incorporate that into your subject line (avoiding sensitive topics).

    You can also include popular holidays / notable dates in your subject line, such as Thanksgiving, Super Bowl, Black Friday, etc.

    Emphasize Scarcity Or Urgency

    Fear of missing out (FOMO) can boost email open rates by 22% and is a common email marketing tactic used in subject lines. FOMO usually works best in subject lines when there is a limited-time sale or a ‘last chance’ to buy something/sign up. However, marketers still need to be aware of triggering spam filters (section above that covers this), you can still use words that create urgency, but within the context of the email and not repeatedly.

    Here’s an example of a subject line creating urgency; using an emoji to stand out and visually show time is running out, an exclamation mark to create urgency, a timeframe (today), and also words that promote scarcity – ‘Don’t miss’ and ‘opportunities’.

    Make sure that your email content matches the urgency of the subject line and do not use urgency as a clickbait tactic. Your email body should further expand on the sale/discount or whatever it is, but continue the urgency to get readers to click through.

    Again, I have come across marketers who suggest not to use ‘jargon’ in email subject lines, but I don’t agree. It should be used where appropriate. If you have a brand that has built an audience around a certain niche, using words that relate to the niche and the audience will stand out and pique their interest. For example, take a look at this example from NVIDIA GeForce NOW (a cloud gaming service), where they use the phrase ‘Final Boss Defeated’ that appeals directly to the gaming audience, which is their target demographic.

    I don’t recommend doing this for every email you send and for some brands that cover multiple niches, it probably won’t work unless you send segmented email campaigns. However, it’s worth testing it with a select portion of your audience to compare the open rates. Search for buzzwords and phrases that are in your niche and relate to the email topic, ensuring they also align with your brand voice and audience.

    Don’t Be Afraid To Be Unique

    You know your audience better than any list of ’email subject line tips’ therefore you shouldn’t feel obligated to follow every suggestion you read. Every brand has its style and voice, and every audience responds differently, so do what makes you stand out from the hundreds of other subject lines. Whether it’s using a different emoji, a joke, or a discount, make your subject line as unique as possible.

    When 64% of recipients decide to open or delete emails based on subject lines, you must do everything you can to ensure your brand stands out from the crowd. 

    Test Your Subject Lines

    Finally, as one of many email marketing tips, you should always test, and the same applies to email subject lines. It’s up to you how many segmentations and variations of subject line you want to send, but it’s always important to do it, especially when you start with email campaigns. Try testing humor vs urgency, emoji vs really short lines, or any other tactics you feel fit with your brand.

    Once you identify the type of subject lines that perform the best, you can use that to inform future subject lines and start becoming more creative.

    Chad Wyatt
    Chad Wyatt
    Chad Wyatt (MBA) is a professional in the digital marketing industry, specializing in content marketing, SEO, and strategic marketing initiatives. With a track record as a 6-figure marketing entrepreneur, Chad brings a wealth of knowledge and experience and has been recognized by renowned media outlets such as CNN, Business Insider, Yahoo, MSN, Capital One, and AOL, where he has been featured for his industry insights and success stories.


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