Best Practices for Email Subject Lines in 2022

When it comes to email marketing, collecting email addresses is only part of the battle. Now you have to find a way to increase opens and clicks. Email subject lines are often the deciding factors in whether or not subscribers click to open. Its purpose is to convince readers that your campaign has value and they’ll benefit from reading it.

Much like to title tag of a webpage or H1 or a blog post, they have to be optimized in a way that encourages engagement. They’re not meant to give all the information to subscribers in one space, but rather to summarize your content or inspire a specific action.

Email subject line best practices

Below, we’ll go over some of the best practices for writing good email subject lines that naturally encourage higher open rates.

Personalize subject lines

Personalization is one of your strongest tools when it comes to marketing. And by this, we mean more than just throwing a subscriber’s name into the subject line, everyone already does this.

If you want to catch their attention and encourage more opens, you’ll need to be more specific. What are their hobbies and interests? What’s going on in their city? Is there a milestone you can reference? These kinds of details are more likely to engage subscribers than something that can be applied to everyone.

With Shout, you can use Merge Tags to personalize email subject lines with the information you’ve stored in custom fields. You’ll have access to all our default tags (like name, email, and company) but you’ll also be able to create and use your own.

Keep them short and sweet

Your subject line should be short, sweet, and to the point. Email clients will only display a set number of characters before trimming the rest of the text, and you don’t want to fall victim to this.

But beyond this, you have to put yourself in your subscribers’ shoes. The average office worker receives 121 emails per day, that’s a lot of subject lines to read through (and you know we really mean skim through).

So, don’t compound the problem by writing something too wordy.

Backlinko suggests that subject lines that do not exceed 16 characters perform better with recipients.

Be descriptive, but don’t give away too much

You want to encourage opens by showing you have something of value to subscribers, but you don’t want to reveal your hand too soon. If you give them everything they need in the subject line, they have no reason to open your email.

A great way to do this is to ask your subscribers a question, like:

“Do you need more organic traffic?”

By doing this, you’ve highlighted the topic of your email and engaged them immediately.

Use action-oriented verbs

Subject lines are very similar to calls-to-action (CTAs), in that they use specific language to encourage readers to take action.

Here are a few examples of action-oriented verbs:

  • Learn
  • Improve
  • Download
  • Increase
  • Join

All of the above words give you a glimpse into the context of the email and inspire people to take action.

Take a look at some other powerful words you can use to capture your subscribers’ attention.

Avoid spammy words

There are also words that you’ll want to avoid using in your email subject lines to avoid being blocked by spam filters.

Here are a few examples of words that may trigger spam filters.

  • Buy
  • $$
  • Extra income
  • Bargain
  • Cash
  • Get paid
  • Passwords
  • Open
  • Opt-in

Take a look at this more comprehensive list of email spam trigger words.

Don’t overuse punctuation

Often, subject lines are written with the best intentions but are perceived in a completely different way by recipients.

Especially when certain punctuation is used, like exclamation points (!).

They can be a great way to convey tone but you don’t know how it will translate when read by others. You might intend to express excitement but you risk it being read as aggression.

If you think it’s adding value to your subject line, by all means, go for it. But only use it once.

The overuse of punctuation can also be a red flag to web servers, and your email may be marked as spam. Plus, this doesn’t look great:

“60% of all products for the next 3 days!!!!!!”

Never use ALL-CAPS

Using all-caps is also bad practice. These subject lines never read well and won’t do your open rate any good. Think about how this looks:


It will catch your recipient’s eye, but not in a good way. Establish trust and build authority with non-spammy subject lines to improve open rates. Don’t use cheap tactics, NOBODY LIKES IT.

Limit the use of emojis

Once upon a time, emojis were a fresh way of making your emails stand out from the crowd. When done right, they can still add something to subject lines, but there is a risk of making your email look tacky.

Here’s where your own judgment comes into play, as there’s no hard and fast rule for this. If your brand or emails usually have a playful tone, you’ll be able to pull this off.

But if you’re just adding emojis so your subject line stands out, you can alienate your audience.

Exercise caution and question what works for your tone of voice.

Couple your subject line with a persuasive preheader text

You’ll also see this referred to as Preview Text, it’s a customizable email field that shows next to or below your subject line in inboxes.

It’s intended for giving recipients a sneak peek of your email content. The amount of text that shows is dependent on the individual’s settings, so you want to pack a punch in the first few words.

Use this in tandem with your subject line to demonstrate everything you have to offer. Not writing preheader text would be a folly, as email clients will pull the first lines of your email by default. That never looks good.

Test email subject lines

It’s always best practice to run your subject lines past colleagues or friends before sending your email. If you don’t have anyone to consult, there are some great free tools you can use to improve your subject lines, for example, OmniSend.

You’ll also want to track the performance of your subject lines after you’ve sent the campaign. Email open rates can be a good indication of how effective your subject line is.

Finally, you should also consider A/B testing. You can use the results to determine:

  • How long your subject lines should be
  • What phrasing works best
  • What power words you should use

Split testing isn’t a one-stop-shop, ideally, you would be testing for each subject line, but that can be time-intensive. So, we recommend that you perform an A/B test for your most important campaigns.

Writing email subject lines that increase open rates

Now that we discussed the best practices for writing subject lines, let’s get stuck into some specific tips for increasing your open rates.

1. Create a sense of urgency

Creating a sense of urgency in your subject lines encourages subscribers to take action. If you state your offering and put a time limit on its availability, people will want to act before they miss out.

Here are some keywords that create a sense of urgency:

  • Expiring
  • Last chance
  • Limited time
  • Now
  • Still time

Don’t flood inboxes with constant updates. This applies to your current email series and any others you may have plans.

The number of emails you send should be based on the length of time you have set.

For example, if your recipients have 5 days to claim a discount, you should send one email at the start of this promotion, then one just before the discount is about to expire.

You want to send enough emails to ensure you’re at the forefront of their mind, but want to avoid spamming their inboxes.

Then wait a little while before you use this tactic again. The more often you try to create a sense of urgency, the less effective email subject lines will be.

2. Tap into their natural curiosity

By our very nature, people are curious. If you can find a way to tap into this you’ve taken a big step towards writing compelling subject lines.

One way of doing this is to present an information gap between what you know and what your subscribers know.

Or share interesting stories that want to be read. For example: “How this CEO doubled his business in 3 months”.

It’s absolutely essential that you deliver on the promises you make when using this strategy. If your email content doesn’t live up to the subject line, you’ll lose all the trust you’ve worked so hard to build with your subscribers.

Here’s a great article if you want to learn more about curiosity subject lines.

3. Share offers and deals

If you have an active discount or deals, you should communicate this with your readers in the subject line. People love to save money, so you’re guaranteed to see an increased open rate when using this strategy.

The deals and discounts don’t even need to be something you’re offering for free yourself. Think about other things your readers are interested in or tools they may use (things that are not in direct competition with your own business or offering). Then create a curated list and share those with your audience.

Here’s a list of email subject lines for deals and offers.

4. Tailor to your audience

Low open rates are often a result of low interest. Just because people have subscribed to your email list, doesn’t mean they’re all interested in the same thing. It’s essential that you learn more about your audience in order to create tailored email campaigns based on personal interests and needs.

You can learn more about your subscribers by analyzing what emails they’ve opened in the past and sending similar content.

Or you can just ask them. Send an email asking what content they’re interested in or why they signed up in the first place. Maybe it was because they wanted to be kept up to date or just because they were interested in a series of content. Identifying that will go a long way in improving the way you personalize subject lines and increase open rates.

To go one step further and increase the amount of valuable information you can compile about your subscribers, create a survey to learn more. If you’re concerned you won’t get enough feedback to make an informed decision, take a look at our tips on how to get more people to respond to a survey.

5. Establish your authority

People subscribe to email lists in order to solve a problem, and a lot of the time that problem is a lack of information. You can establish your authority and build trust with your readers by writing timely and relevant content.

Research what’s new in your area of expertise and consider how it could impact your audience. If you can identify something in your research that could be a problem for them, translate this into an eye-catching subject line and allude to the solution you can provide.

Or you can even just compile a list of articles that may be of interest to them and provide snappy summaries for each.

6. Drop famous names

This isn’t always the right choice for your email, especially if the name in question doesn’t relate to your business or brand in any direct way. But, dropping a famous name into your email subject line is a surefire way to increase open rates.

7. Use numbers and statistics

Using numbers and statistics in your subject lines presents a more subjective and descriptive view of your email content.

Research has found that using numbers in blog posts increased clickthrough rates by 206%. Whilst that exact statistic may not be directly transferable to subject lines, we can still infer that you’d likely see an increased open rate using this tactic.

In blog posts, you’ll often see examples like: “15 tips for increasing site traffic”.

You can see this clearly demonstrates value in the content.

Wrapping up

Email marketing is still one of the most effective methods of increasing sales and engaging your audiences. But if people aren’t opening your emails, your time and resources are being completely wasted.

By improving your subject lines, you’re much more likely to increase the chance that people will open and read your content.

To do this, your first port-of-call should be to adhere to the best practices for email subject lines:

  1. Personalize subject lines
  2. Write as if you’re speaking to an individual or exclusive group
  3. Keep them short and snappy
  4. Describe your content, but don’t give away too much
  5. Use action-orientated words
  6. Avoid spammy words and phrases
  7. Don’t overuse punctuation
  8. Never use ALL-CAPS
  9. Limit the use of emojis
  10. Couple your subject line with persuasive preheader text
  11. Test your subject lines

Once you’ve followed these best practices, you can then focus on strategies for increasing your email open rates further:

  1. Create a sense of urgency
  2. Tap into their natural curiosity
  3. Share offers and promotions
  4. Tailor content to your audiences
  5. Establish your authority
  6. Drop famous names
  7. Use numbers and statistics

Now that you know the specifics of writing email subject lines, you need to evaluate your email marketing campaigns as a whole. Take a look at our complete guide to email marketing.