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How to write high open rate email subject lines that get you sales

How to write high open rate email subject lines that get you sales

min read

🚀 SKYROCKET your open rates by reading THIS BLOG! 🚀

Did you cringe? Same here.

We’re all a little sick of over-the-top sales messages in our inbox.

But salespeople have to grab their prospect’s attention somehow – and data tells us the subject line is crucial. It’s the lynchpin of any email outreach campaign. 

There’s a way to write effective subject lines without relying on tired clichés and sounding like an over-excited robot.

This blog will show you…

  • What often goes wrong with email subject lines
  • How to write high open rate email subject lines
  • Tips and tactics from experts in the field
  • How to test and learn what's working

Your subject line is the first thing your prospect sees. Let’s make sure it isn’t the last.

Think you’ve got a catchy sales email subject line?

So, you think you can write email subject lines for high email open rates?

Are you sure? Because 47% of recipients open an email based on the subject line alone. And 69% of recipients report an email as spam based solely on the subject line.

So it might be worth going back to the drawing board and finding a way to optimize your subject lines if you want your sales outreach or cold emails to have impact.

Let’s take a look at:

  • Why email subject lines are crucial to sales
  • What you might be doing wrong
  • Important questions to ask about your email subject lines

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Why email subject lines are crucial to sales

Your email subject line is crucial because it’s your first impression. A bad subject line is essentially a really awkward handshake.

Are you going to sell your product or even get a chance to pitch your product after an introduction like that?

Let’s hammer home how important a high open rate email subject line is:

  • Number of emails the average prospect receives per day: 121
  • Average conversion rate of cold emails: 15.11%
  • Average open rate of cold emails: 24%
  • Average response rate of cold emails: 1%

One. Percent. Only one percent of your emails are absorbed and replied to. 

Since subject lines have a major influence on open rates, the success of your email marketing strategy often boils down to the effectiveness of your subject lines. 
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What you might be doing wrong

Many of our email subject lines end up being too pushy and, well…sales-y. We forget that we're humans writing for humans, not some sales machine writing for an abstract persona in our customer journey.

Lines like: “Want to improve revenue, Dan? Only one click to a better annual profit!” make most people groan.

It doesn’t sound natural and it doesn’t sound enticing. Sounding relatable and human is always the way to go.

Even if your email newsletters are carefully crafted and well written, there are still a few common (yet crucial) technical mistakes that could be hurting your open rates.

A screenshot of the newsletter template sample in Streak mail merge tool

Where could you have gone wrong…?

This sort of template error can be avoided with a mail merge tool.

Mail merge allows you to include variables like your recipient’s first name, their business name, or the product or service that would best fit their needs.

A good mail merge tool will point out any errors before you hit ‘Send’, allowing you to avoid embarrassing mistakes.
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Important questions to ask about your sales email subject lines

Before hammering out a subject line in a few seconds and diving right into the body of your email – stop and think. 

Try to think from the email recipient’s point of view and what they might like to click on.

Ask yourself these 4 important questions:

  1. What problem are you actually solving?
    Rather than listing your products or services, focus on value with the pain point you can solve or how you can improve a certain process.
  2. Who are you selling to? 
    Identify your decision-maker, their professional background, and anything else you can dig up about how they work.
  3. Would you delete your email?
    You can learn a lot from your own inbox. What are the subject lines you never open? Which ones catch your attention?
  4. How can you motivate the prospect to respond?
    After conveying the benefits of your product or service, are you offering a discount or limited-time opportunity? 

Pausing to answer these questions can help you recognize what to focus on when crafting your email subject lines. 

But if you have the time, consider 4 more helpful questions to take you even further:

  1. Is your recipient already familiar with your business?
    This helps determine whether or not this email is the first impression.
  2. Do you have any mutual connections?
    Finding common ground and referencing it in your subject line drastically improves open rates.
  3. Why should they want to open your email?
    It could be a cliffhanger or just a really relatable line – either way, your email subject line should be irresistible.
  4. How will you track which subject lines work best?
    If you found a subject line that works, you’d want to know about it, right? Tools like email view tracking show you how your subject lines are performing so you can pick a winner and start to identify patterns.

Sometimes it’s hard to remember your customers are real humans when you’re sending messages from the comfort of your desk. But they’re people, just like you.

Give your subject line a quick gut-check to see how you would respond before hitting send.
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6 ways to write the best email subject lines to increase your open rate

So, now you know what not to do. You’ve asked yourself some key questions and you’re in the right mindset.

“Okay,” you say, “But really, which subject lines get the most opens from leads?”

Writing email subject lines that resonate with your recipients requires experimentation and fine-tuning. The best way to increase your open rates is to try different tactics and measure your results.

There's no one-sized-fits-all answer or magic equation to writing a great subject line, but a few tips and tactics have been proven to help your email get more views.

After reviewing data and advice from some experts in the field, we identified the top 6 tips for the next time you’re writing catchy email subject lines for sales:

  1. Personalize your message
  2. Make it mobile friendly
  3. Be honest and keep your promises
  4. Introduce yourself upfront
  5. Strike a casual, relatable, and human tone
  6. Keep it short and to-the-point

1. Personalize your message

Research shows that people are more likely to open an email with their name or their company’s name in the subject line. 

  • Using your prospect’s name in the subject line increases open rates by 20%
  • This translates to an increase in sales leads by 31%
  • And a reduction in the number of individuals unsubscribing from the email campaign by 17%
A screenshot of a personalized email subject line


Personalization piques almost everyone’s interest and is useful across all industries, from large eCommerce brands to individual salespeople.

It can also take many forms, which presents a great opportunity to get creative and try out a few different tactics. You could try including your prospect's: 

  • First name
  • Business name
  • Industry
  • Pain point
  • Goal

The most common form is the prospect’s name or their company’s name. However, people are becoming more used to seeing their name in a subject line, which may affect open rates as behavior changes. If you’re willing to put in the extra effort, try personalizing with the prospect’s goal or pain point in mind.

For example: “Social media schedule”

This gets right to the challenge of consistently scheduling social media posts and is directly referencing their issues and pain points.

2. Make it mobile-friendly

81% of people prefer to open emails on their smartphones, and yet optimizing for mobile can be an afterthought for many sales reps and email marketers.

With more and more web and email behavior shifting to mobile devices, it makes sense to format your sales emails for mobile devices. That doesn’t just apply to the body of an email – the subject line has to look good on mobile, too.

Don’t believe us?

A screenshot of the fill-in template for the email sender name, subject line, and pre-header text


Let’s see how this template translates to a standard iPhone screen.

A screenshot of the translated template for the sender name, email subject line, and pre-header text on an iPhone screen


Maybe not what you were going for.

The takeaway here is – subject lines look different from computer to smartphone. How the subject line looks can even differ based on the brand and model of smartphone that your prospect is using.

Try testing out your email draft and subject line on a free marketing tool like Zurb’s Test Subject. This allows you to test your subject line on different mobile screens before hitting send.

3. Be honest and keep your promises

Getting email subject lines right is so much more than convincing people to open the email.

Let’s face it, if we only cared about open rates and nothing else, we’d just tell you to use “[First Name] - you’ve WON!” and be done with it. 

But if your actual email starts with: “You’ve won a free appointment and product pitch with our Account Executive," you’ll lose prospects faster than you can say ‘cheap clickbait’.

Having an epic subject line will get eyes on your email, but you need to be able to keep your promise and offer real value – quickly.

Instead, you can use email subject lines like: 

  1. Follow-up offer you should consider”
  2. “[First name], a question about your marketing solution”

Both add intrigue and entice interest, and at the same time, they’re promises you can easily keep.

4. Introduce yourself upfront

If the prospect is already familiar with you or your company, sliding your name right in the subject line will help them identify you and can do wonders for your open rates.

Your company’s name will be noticeable among all the promises for “74% off” and “Only 2 days left”.

Adding your company name in the beginning of your email subject to help it stand out as your prospect sorts through their 121 daily emails.

A few examples are:

  • “Streak: Call Today”
  • “Streak: Follow-up”
  • “Streak: Proposal”
  • “Streak: New Product”

After you’ve actually broken through the nigh-impenetrable “cold” portion of outreach, it would be a shame to get lost in a sea of Twitter notifications and antivirus offers.

5. Strike a casual, relatable, and human tone

“Derek, love to chat about marketing automation

What vibe do you get from this subject line? 

It’s friendly, warm, and sounds like an actual person that you’re talking to in real life. It's the first step of making a real connection.

Let’s look at the contrast:

“Boost ROI to the moon with our strategic marketing automation solution!”

See the difference?

Successful subject lines sound more like humble friends or trusted colleagues and less like a hacky guru slinging NFTs and offering unsolicited business advice.

Avoid rattling off lists of percentages and cringe-y buzzwords like “strategic”, “unique”, and “guaranteed”.

Here are a few quick pointers to help you sound more human and approachable in your email subject lines:

  • Be humble, it might not work out
    Example: "Interested to see if there's a fit"
  • Benefits > features
    Example: "Our customers see at least 12% reduction in admin time"
  • Empathize with pain points
    Example: "Putting your house on the market can be overwhelming"
  • Show curiosity
    Example: “Curious how you're solving this problem at the moment?”

6. Keep it short and to-the-point

Unsurprisingly, we tend to skip over emails that look like they're trying to sell something.

"Normal" looking emails get opened. Will Allred, one of the heads at Lavender, uses a tactic he calls "Internal Camo" to create email subject lines that don't arouse suspicion.  

The idea is that your subject line is so straightforward, so not sales-y, that it looks like it could be from a team member internally.

Here's how:

  • 2-3 words
  • Boring
  • No verbs and adjectives
  • Neutral tone

Some examples: 

  • Mail merge tool
  • Breakup email copy
  • Email tracking data

What? No emphatic words like ‘skyrocket’ or ‘killer’ or ‘ultimate’?

After all, when’s the last time you received an email like that from your co-worker?

The "Internal camo" strategy isn't meant to trick your email recipient into thinking you're actually their co-worker, but it makes sure they aren't turned off by a gimmicky subject line so your email has a chance for success in their inbox.

Bonus tip

If you make a mistake in your email subject line right after hitting send (we've all been there...), you can correct the problem before it’s too late. 

Check out these 6 Gmail tricks to learn how to undo sending an email and other quick tips to save yourself time and a few headaches.
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How to make sure your email subject lines work

So you’ve created a few catchy subject lines – how do you know what's working so you can continue to increase your open rates?

A few methods and tools can help you measure open rate success:

  • A/B testing email subject lines
  • Email analysis tools
  • Talk to your prospects

A/B testing email subject lines

A/B testing, also known as split testing, is a data-driven way to increase your open rates.

A/B testing compares two or more variations of something. You can run A/B tests for subject lines, a call to action, the format of your email, images, colors, or anything else you want to optimize in your email.

A screenshot of the mail merge page list

To A/B test a subject line, craft two different subject lines and send them to similar groups of people by splitting your audience in half. After a set period of time, compare your open and response rates. A mail merge tool or email marketing tool can help you do this.

Once you’ve run your A/B test, you can use the most effective subject line in your emails to increase your open rates.

Streak facilitates simple A/B testing with our mail merge feature, which allows you to easily send tracked, personalized mass emails in Gmail.

You can check out the tutorial for mail merge here.

Email tools

There are email tools out there that rank email for tone, clarity, and mobile responsiveness. Comparing them against millions of successful emails and then suggesting ways to make them more impactful.

Remember how we mentioned Lavender earlier? Yup, they’re one of those tools.

It features Subject Line Analysis, Spelling & Grammar Check, Mobile Preview, and more. You can start using it now for free to see how your current subject lines are stacking up.

Talk to your prospects

It’s simple: when you get a positive response, ask them what caught their attention/what they liked about the email.

Your prospects and leads are hidden resources just waiting to be tapped into. No one can provide you with more useful feedback and marketing tips than the people you’re marketing to

It’s invaluable to you and can make you seem more relatable to your prospect. You can be super professional and serious about it. Or you can make it lighthearted like:

“Sooo…remember when you first replied to us? What made our email stand out from the others?”

You’ll probably get some pretty useful feedback.


Writing catchy email subject lines for sales doesn’t have to be a headache. 

Adapting tips like personalization, mobile formatting, and internal camouflage into your next outreach session is simple, effective, and definitely worth your time to practice.

When in doubt, give it a gut check to see if it's something you'd open in your own inbox.

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