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Email Subject Lines: 8 Tips to Captivate Your Audience in the Inbox

Email subject lines are the most decisive factor in determining whether or not a recipient will open your email. Here are 8 tips to help you stand out from the crowd and boost your email open rates!

email subject line and preheader in the inbox

People are constantly being bombarded by emails every day, which means it’s becoming more and more difficult for email marketers to get noticed among all of the competition and convince readers to open their message.

The most visible, and arguably the most influential, element that contacts see for your email campaign is the email subject line. This also makes it the main factor that you can tweak to improve your open rate and get more engagement when sending an email newsletter or bulk email campaign.

In this article, we’ll give you 8 tips to help you construct email subject lines that will:

  • Grab readers’ attention
  • Convey a higher quality level of content in your message
  • Convince recipients to open

1. Keep it short

A good email subject line should be rather short to keep the reader’s attention and avoid being truncated by email clients (i.e. Gmail, Yahoo, Outlook, etc.).

In theory, there is no formal limit to the length of your email subject line (though some tools will place their own limit on how much you can input to the field).

In reality, long subject lines will never be read in full anyway because different email inbox software providers are only capable of displaying a certain number of characters before the text is cut off.

Email subject line character limits by email client

Email client Number of characters
Gmail 77
Outlook 60
Yahoo 47
Hotmail 45

As you can see, there’s not much to work with here. And when you take into account the fact that mobile email clients (which account for a significant portion of email consumption these days) display even fewer characters, you can start to understand where we’re coming from.

That’s why we recommend you limit your email subject line to 50 characters or less. This will allow you to focus only the essential information and optimize for engagement.

truncated subject line example

2. Put the most important information first

Highlight the most important information that you want to communicate up front in your subject line to maximize chances that people want to engage with your content.

For the same reasons that you want to keep the subject line short, you should also put the most important information first. Since you have no control over the number of characters that will be displayed to the reader, the only thing you can do is highlight what you want up front so they have the highest likelihood of seeing it.

Additionally, users tend to only take a glance at the subject line, so the first few words are where you want to capture their attention with the most important stuff.

By “important,” I mean anything that will effectively capture the reader’s attention quickly:

  • The main point of your email
  • Details about a promotional discount
  • A date or time limit expressing urgency
  • An intriguing phrase that piques the reader’s curiosity

Here is an example of a subject line that starts with the information that’s most important to users (and therefore more likely to grab their attention):

email subject line showing most important information up front

3. Avoid using spam words

Spam words are the words that email inbox providers use to check whether a message is spam — and they also usually give readers a bad impression of your email as well!

The last thing you want as an email marketer is to be perceived as a spammer by your audience. But, depending on the language you use in your email subject line and message, your readers might be thinking just that.

Certain words that are known to be associated with spamming can often trigger a sentiment of skepticism among recipients, and even worse, they can lead email inbox providers like Gmail to relegate your emails straight to the spam folder. These words include things like:

  • Free
  • Promotion
  • Hot
  • Casino
  • Urgent

I think you get the idea. 😉

If you can, try to avoid using this type of language, especially in your subject line because it will likely hurt your campaign’s engagement rate.

4. Spice things up with emojis

When used with proper discretion, emojis can give your email subject line more visibility in the inbox, making it more expressive and attractive to potential readers.

Like any marketing advice, you need to first consider your audience before integrating this tip into your email marketing strategy. You don’t want to give the wrong impression. For example, if you’re a financial advisor, your clients might not want to see a smiley face in the subject line of your emails!

However, if your brand has a lighter marketing approach, then emojis could be the perfect way to supercharge your email subject line and improve your open rates.

Not only are emojis great for quickly communicating an idea with fewer characters — making your subject line more concise and leaving you more room for other information — but they also help you objectively stand out from other subject lines that only include text.

emoji in subject line for inbox visibility
Which subject line stands out most from the crowd?

You can also get around the problem of communicating information requiring spam words — just replace them with emojis!

  • ⏲ can replace “urgent”
  • 🎁 can replace “gift”
  • 🔥 can replace “hot” or to convey the popularity of certain items

But, be careful when you start including emojis in your emails and subject lines! Depending on the device and the email client, emojis may be rendered differently. To make sure you’re getting it right, check out our full article on how to properly use emojis in your email marketing.

5. Keep it simple and professional

Don’t overdo it with excessive capitalization, special characters, or punctuation in your email subject line.

Just because something helps you stand out in the inbox doesn’t necessarily mean it’s a good idea to implement in your subject lines! Sometimes, quick “hacks” that might, in theory, give you more visibility can actually have very negative consequences.

For example, including things like, “EXCLUSIVE OFFER” and “LIMITED TIME ONLY,” or you add too many special characters, such as “SAVE $$$$,” you could actually end up being classified as spam.

And even if you make it to the inbox, this type of email subject line content isn’t likely to leave a great impression with your contacts.

6. Piggyback on current events and seasonal trends

Current events in the news or pop culture can be a great source of inspiration for writing captivating subject lines for your email marketing campaigns.

When interacting with other people in daily life, it’s not usually all about work. Although it’s always good to mention relevant trends in your industry in your content, you don’t have to make it a rule.

If you talk about things that are happening in the world outside of your particular industry or niche, it’s a great way to connect with your audience on a more human level. It shows them that you’re not just a faceless company with not personality, but rather that you’re a person existing in the same reality as them (sounds a bit weird when I say it like that though 😅)!

And it doesn’t have to necessarily be current events in the new or pop culture. You can also reference season events like holidays or weather (winter is cold… am I right?) to achieve the same goal!

seasonal reference in the email subject line
Volcom makes a simple reference (and a nice double entendre) by referencing the “chill” in a January campaign.

7. Make it personal

Adding little bits of personalization, such as a first name, in your email subject lines can often have a positive impact on your open rate.

Seeing our name or something relevant to our interests in an email subject line can make the content feel more relevant. This will often catch our eye more effectively and increase the desire to click.

With Sendinblue and most other email marketing software providers, it’s quite simple to dynamically inject data attributes that you have stored in your contact database (e.g. first name, topic of interest, city of residence, etc.) for each individual contact.

This means you can type something like {{contact.FIRST_NAME}} in your subject line, and your email tool will automatically add the name of each recipient based on their contact details! It looks something like this:

First name included in a subject line

But, like any marketing tip, be sure that you don’t overdo it and use this all the time. If you start including first names in the subject line of every campaign you send out, it’s going to lose its effect pretty quickly.

8. Choose sustainability over quick wins

If your subject line generates a higher open rate but hurts the relationship and trust that you have with contacts, it’s time to go back to the drawing board.

This is probably the most important tip I can give you: a good email subject line isn’t just focused on maximizing the open rate of your email campaign. It should also build trust and set your email up for success in terms of engagement and conversion (hopefully you want people to do more than just open 😉 ).

Avoiding clickbait tactics or other things focused on short-term gains is the best way to achieve this and continue reinforcing your contact relationships.

The most common example of this in action is when a subject line creates false expectations that are subsequently not met by the email content. Intrigue is a very powerful sentiment, but you need to make sure that you give the reader the wrong idea. An example of this would be using a subject line like, “You’ll never guess what we’ve got for you!” for an email that simply promotes a new product.

This type of interaction can really hurt your brand in the eyes of your contacts, so you have to be very careful and always take a customer first approach.

Need an email marketing tool to start sending your newsletters and campaigns? Try Sendinblue today — it’s free for up to 9 000 emails per month!

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2 Responses to “Email Subject Lines: 8 Tips to Captivate Your Audience in the Inbox”

  1. Lee Bowden

    I found this really helpful! I’m going to dabble with some emojis, which i never even thought of until now! We have a few we use consistantly on Twitter, so I feel this would be a way to personalize us even further.

    Awesome post. Great blog. Thanks SIB

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Email Subject Lines: 8 Tips to Captivate Your Audience in the Inbox

time to read: 7 min