80 Cold Email Subject Lines to Increase Your Response Rate

Created On
January 20, 2023
Cold Email Subject Lines

Want to increase your open rates? 

Then work on cold email subject lines. FYI, 69% of email recipients report an email after reading the subject line. So, the key to successful email marketing is the subject sentence. 

Read ahead to find important data related to email subjects and samples based on them to ace your next cold email campaign. But, before you do that, here’s a quick summary of the importance of subject lines. 


80 Cold Email Subject Lines to Increase Your Response Rate

Cold emails are emails sent to potential customers with whom the sender had no prior contact. Consider the subject sentence as the first impression. In cold outreach, the first impression is 99% of times the last impression, which is why it's so crucial to nail it with the subject sentences.

In this section, I have discussed in detail about catchy, personalized, intriguing, informative, and short subject lines. Here's a quick overview.

Catchy Cold Email Subject Lines

33% of recipients open an email if the subject is catchy enough. Now, what makes a subject catchy? 

Bitter Truth

Sales, in general, include a hyper-positive interaction with the prospects with little to no “NO” or mention of anything that can make the target upset. 

So, one of the best ways to catch the recipient’s attention is by doing the opposite. That doesn’t mean you can say sentences like

❌You will go bankrupt if you do this

❌Recipients will block you if you don’t do this

❌You know nothing

Instead of saying extreme things like the above, you can say something that is relevant and refers to a bitter truth. 

  1. Your emails suck: Why you need to personalize 
  2. Why your kitchen is more automated than sales 
A WORD OF CAUTION ☠️: Never use sentences that have the potential of ruining your relationship with your customers. 

Reference to Trends

Image Credits

Something that’s going in the news or viral in Tiktok is popular and catchy. You know that people are already hooked on this topic. This is why, when you are in doubt, it’s safe to use subjects that refer to a current trend. 

Here are some subject line examples: 

  1. Covid is killing the economy. What are you doing about it?
  2. This is how Zuckerberg started

Why will the above sentences work? 

Let’s talk about the first sentence first. So, the economic crisis because of the coronavirus pandemic is a universal thing. Be it Australia or Nigeria, businesses suffered losses all around the globe. 

By saying “Covid is killing the economy,” you have made sure that the recipient, irrespective of their demography, is going to stop scrolling after reading this line. The part of the sentence “what are you doing about it?” makes the reader question themselves and take action. 

The second subject is guaranteed to work if you are targeting a start-up founder. Zuckerberg is still a wonder to many, especially entrepreneurs, how he managed innovation and success at such a young age. The point is that everybody wants to know. 

Everyday Phrases

Email is something that we always go a little formal or official. So, when scrolling through the inbox, something very ordinary such as everyday phrases can catch the recipient’s attention immediately. This type of subject lines work magically for cold sales emails.

Some of the examples can be:

  1. Let’s get a cup of coffee
  2. You okay there? 
  3. We need to talk 
  4. I got your back

Reference to Popular Culture

Talking about catchy subjects, popular culture references always work. Obviously, when your recipient gets the reference, otherwise, it’s all lost in translation. ‘

  1. Be the Jim of your sales team
  2. That’s what the customer said
  3. Carpe diem the weekend sales
  4. Could you be more relaxed?

Use Emojis

Although many B2B people claim emojis are a risky thing, this practice can yield great results for B2C marketers. But, of course, implement this keeping in mind your brand image. 

For instance, the audience base of fashion e-commerce might like to see emojis, but customers of yoga teachers might not. Again, use emojis CAREFULLY. Some of the ways users can use it in your subject lines are:

  1.  ⚠️ Last chance! Black Friday sales end in 5 hours 
  2. ❣️ Valentine's day sales are live!
  3.  Find your comfort in the wild ⛺
  4.  🐈 Pamper your pets within your budget 🐈 
  5.   Top 10 Summer trends 🌞 you need to know now
Check out “101+ Cold Email Templates” to Nail Outreach with Ready-Made Templates. 

Personalized Subject Sentences

Image Credits

Did you know 74% of marketers saw customer engagement improvement through personalization?

That’s right; it’s the biggest trend in email marketing right now. If you want to ace cold email outreach programs, you need to start using personalized subjects. 

How to personalize subject lines?

Use Names

One of the most common ways of personalizing email content is to refer to the recipient using their first name

  1.  Jon, you need to check this out. 
  2. Mark, is there too much on your plate? 
  3. Levy, how does a 5x increased ROI sound to you?
  4. Hey Ross, {mutual connections} says we need to collaborate
According to statistics, around 26% of leading cart-abandoned email subject lines are personalized. If you are an owner of e-commerce or other business-to-customer companies, then using the first name will do wonders. 

However, that’s not enough if you’re a business-to-business marketer. 

Use Business Information

For B2B marketers, personalization needs to go a little deeper than usual. You need to use their business-related information such as their company size, annual revenue, company history, current needs, etc. 

Some of the ways of doing that are: 

  1.  This tool will help with the expansion
  2.  Your website needs exit pop-ups
  3.  Your website needs a list-building tool
  4.  Is there too much pressure on your sales team? Automation can help
  5.  Congratulations on your first birthday! 
A WORD OF CAUTION ☠️: You can use any information you want but try to limit yourself to using ones that are available on public platforms, such as LinkedIn, Ambition box, Glassdoor, Twitter, etc. 

Refer to Current Events

Besides using names and business-related info, referring to current company events is another way of personalizing subject lines.

  1.  Congratulations on {so-and-so industry-related recognition}!
  2.  This tool will help with {recent company event}

But, talking about the company might not work all the time. If you are targeting a decision maker, it’s effective to personalize the subject line specifically for them. Here are some ways you can do that.

  1.  Congratulations on the promotion!
  2.  Huge fan of your {work} on {so-and-so platform}
  3.  You did a great job with {recent achievement}!

Please note that you can use similar subjects for networking emails too. 

Intriguing Subject Sentences

Subject lines should be intriguing. It should make the reader curious enough to open the email. You can make the recipient curious in several ways, here are some of them. 

Talk About Competitor

One of the primary ways of using the competitor company’s name in the subject line is by mentioning what they achieved using a particular service or product. Take a look at the example below. 

 1. {Competitor} gained 1k customers/month using automation tools

This sentence is guaranteed to make the recipient curious enough to open the email. Firstly, you are mentioning the competitor that they always wanted to beat. Secondly, you’re also mentioning a target that they have always been trying to achieve. 

Now, the above subject line will work only if you do your research (about the company) thoroughly. You must not go wrong with the archenemy company and the goal. 

Another simple alternative to this is:

  1.  {Competitor} uses {name the product}
  2.  Our clientele includes Facebook & Twitter. You can join too
  3.  Facebook like {so-and-so tool}

Remember, this line will bag a response but you must get the competitor's name right. Some other ways of using a competitor’s name in sales subject lines are:

  1.  {Competitor} achieved {this goal}. Let us help with that
  2.  {Competitor} won {so-and-so award}. You can do too
  3.  {Competitor} was listed in Forbes. You can be there too

Talk about the Industry Legends

If you think using a competitor company’s name is kinda risky for your first-ever email to the prospect, then you can use industry legends. 

For instance, if you’re targeting a pet products business owner, it’s better to go with companies such as Mars Pet or Nestle Purina pet products. 

  1. Mars Pet uses {this service. You should too
  2.  Mars Pet achieved {goal}. Let us help you do that

Another way of doing this is by referring to industry experts’ names in the subject. For example, if the recipient is a salesperson or head of the sales team, you use names like Grant Cardone, Zig Zigler, etc., in the subject lines. 

  1.  Grant Cardone thinks {this tool} is useful
  2.  Neil Patel uses {this service}
  3.  Check out Neil Patel’s secret tool 

Using experts’ names in the subject line is an effective way to increase your open rates. However, never mislead the prospect. When they open the email, eventually, they don’t want to feel cheated. 

Therefore, it’s necessary to stick to the truth only, which means if you want to use Neil Patel’s name in the subject line, it’s better to get his reviews or recommendation. 

Create a Sense of Urgency

Creating a sense of urgency might be the oldest trick in the sales books but it works all the time. You can try the same for writing an effective subject line. 

  1.  Beware of {problems} this holiday sale
  2. This might save you from loses

The above example alerts the recipient about certain problems which they are more likely to face during the “holiday sales.” 

Besides showing your goodwill (of helping people), it also shows that you’re an experienced individual in that matter. These reasons are enough to make the reader curious about the email body. 

  1.  Final hours: 50% off is almost over
  2. Last chance to win 30% off in yearly plans

The "limited time" subject is the classic example of creating an emergency in sales. 

  1.  You need to check this out before the end of this quarter

The above subject creates suspense. You aren’t even letting the recipient know what they need to check out. Just make sure you have something to offer that will help resolve a pain point they are facing during the quarter. 

Create FOMO


FOMO or fear of missing out. In a Forbes article, Latane Conant, the CMO of 6th sense, explains in detail how even B2B marketers tend to make purchases in fear of missing out.  

And, what’s the easiest way to create FOMO other than reviews from famous names? 

According to studies, around 92% of consumers check product reviews before purchasing a product or service. So, if you want to create FOMO in our email outreach programs, I suggest you use something like this:

  1.  {Competitor} is saving 50% expense with {this tool/product}
  2.  {Our tool} is trending 
  3.  Did you know {tool} is used by 10k and more companies
  4.  10 things you didn’t know about email marketing
  5.  You should know this
  6.  {Competitor 1} & {Competitor 2} are using {this tool} 
  7.  5 email marketing trends you should know before 2023

A little exaggeration is okay while writing such subject lines but don’t lie, especially if you’re planning to keep the prospect in the long run. 

Talk About the Pain Point

Sales are probably 50% of your sales techniques/skills and 50% of your research skills. If you can research and find out important things about your potential customers, then it's bingo. 

Talking about finding things about your future customer, the pain point is the most crucial one. It’s like hitting the bull’s eye if you can do that. 

The common pain point area for B2B sellers are:




✔️Customer support

✔️Data tracking

The best part of targeting pain points while cold emailing is that it gives you a thread for your follow-up email. Take a look at some of the examples:

  1.  Struggling to keep track of {pain point}?
  2.  Stop guessing the open rates today
  3.  Tired of higher bounce rates? Start A/B testing today
  4.  Tired of landing in spam? I can help
  5.  Dan, let me help you with {pain point}
  6.  10 tips to solve your {pain point}
  7.  A better idea for {pain point}
  8.  I can help cut 40% annual cost
Struggling with cold emailing? 
Check out this
checklist to nail it in your next attempt. 

Informative Subject Sentences

The intention of cold emailing might be selling your product but that doesn’t have to start that way. Sometimes, especially for high-quality leads, you should try building a relationship by sending value-added products. 

Remember, your goal is to make them open the first email so that you can send follow-ups, bag a response or two, and eventually sell to them. If you want to turn your prospects into loyal customers, try using the below cues in your subject lines. 

Industry news

Most B2B prospects were industry professionals or experts and right now, they are busy running a business. So, if you can curate relevant industry news and save their Forbes-reading time, it would be a win-win situation for both parties. 

  1.  Did you know {industry expert} won this award?

If you can find out the niche the prospect is interested in; the above subject will work for sure. 

  1.  CEO {Name} is reluctant to work in {big company’s name}
  2.  {Big company’s} co-founders regret expansion
  3.  {Competitor} got listed in {industry-related recognition}
  4.  {Big name} wants to sell {company}
  5.  {Company} fires 100 employees for moonlighting 

The best way to use this type of subject line is in newsletters. It will provide value and will help in creating a loyal audience base. 


Here’s how you can use recent trends in the subject lines and increase your open rates. 

  1.  You want to know the top 5 Sales Trends in 2023
  2.  Stop what you’re doing. {This tool} is the newest trend
  3.  {Competitor 1} & {Competitor 2} are using {this software}

Content [audio + video + blog posts]

Sending relevant (cum value-adding) the content in your introduction email to a cold lead is a good strategy. Relevant content in the email sends a message that you have done your homework, you’re professional, and you are there to help them.

B2B prospects are aware of the marketing trends, and they value the recent trend of customer-centric marketing. Try this and thank me later. 

  1.  I saw your post on {topic}. This {content} might help 
  2.  Recent marketing statistics to help your business
  3.  Resources about {so-and-so topic} you need to read right now
  4.  Proven tips to help your {pain point}

The other ways of writing informative subject lines are talking about webinars, classes, and free resource material. You can also talk about product demos. 

Short [Less than 60 characters]

Want to ace outreach email campaigns? 

It’s time to rethink the length of the subject lines. 

Apparently, 82% of marketers do not exceed 60 characters while sending emails to cold leads. 

I think there’s a reason behind it. 

Think about it. Your potential customers are swamped with sales emails from strangers they don’t know anything about. So, your email is definitely not landing in the primary inbox. It’s either in the “promotional” or in the “updates” section. 

As we all skim through the promotional and updates section, our prospects do the same. Now, do the math on how many seconds you get to catch their attention. It’s definitely not more than 1 second. That’s the time you get to make them reach your subject lines. This is why it’s utterly important to keep them within 60 characters. 

  1.  Hey Dany, we should collaborate
  2.  Have you seen this {article/video/podcast}?
  3.  Quick question regarding your {so-and-so project} 
  4.  Are you prepared to welcome {so-and-so period}?
  5.  Tim, let’s cut to the chase
  6.  What’s your process for cold calling?
Wondering how to write follow-up email subject lines?
Check out this article to learn A to Z about follow-up subject sentences.

How to Test an Email Subject Line? 

The success of cold outreach campaigns depends on picking the right subject line. But, how does one know which is the right subject sentence for your campaign?

Fortunately, you don’t have to listen to your gut feeling to pick the right subject for email outreach. Instead, you can just do A/B testing with subject sentences using a cold emailing software like Smartlead. 

A/B testing or split testing is a feature present in cold emailing tools that allows you to test two or more variants of the same email sent simultaneously. Using this feature, you can determine which subject sentence yields better response rates and click-through rates. 

You can use the same feature to test cold email copywriting, in general, personalized opening lines, call-to-action (CTA) messages, or even the complete email sequence if necessary.

Here’s a step-by-step process on how to do A/B testing to test email subject variants. 

Choose a Cold Email Tool

Choose a cold email tool to send 1000s of emails without getting blacklisted. Make sure the tool has features like

  • Warm-up
  • A/B testing
  • Automated follow-ups
  • Auto-mailbox rotation
  • Multi-channel outreach
  • Master inbox
  • API Access
  • Unlimited Seats
  • Webhooks & Integrations

Set Up Your Account 

To start sending cold emails with an outreach tool, start by creating an account on their platform. Afterward, establish a connection between the tool and your email service provider (ESP).

Do the SPF, DKIM, DMARC & MX set up for better email deliverability, and enhance the overall security and trustworthiness of your email communications. 

Warm Up 

It's crucial to prepare your email account before launching a campaign or sending out bulk emails. Make sure to gradually warm it up over a period of two weeks.

Create the Email Campaign

In the software, find the “add campaign” option and click on it. 

Import your Email List

Upload your email list to the cold email tool, ensuring it's properly segmented and organized. The lead list must be in csv format like the below file. 

Write the Subject

Write a catchy, short, subject for the email campaign. 

Write the Email Body

Write the email content, including the body of the email and the call-to-action (CTA).

Create Subject Line Variations

Develop two or more distinct subject lines for the same email content. These will be your A/B test variations.

Set Up A/B Test

Look for the A/B testing feature within the cold email tool. It might be under or at the side of the campaign settings.

On Smartlead, you can do A/B testing by creating variants. 

Click on the "add variant" option.

To test subject lines, you can keep the email body same but only change the subject sentence in the next variant (variant 2).

Once you have created the email variants, click on save & next and you are done. Check once before scheduling the emails. Set the timing keeping in mind the recipient’s time zones. 

Monitor Performance Metrics

Keep an eye on key metrics such as open rates, click-through rates, and engagement. The cold email tool should provide real-time data.

Compare the performance of the two subject line variations. Determine which one had higher open rates or other relevant metrics. If one subject line clearly outperforms the other, use that knowledge to improve your future email subject line strategies.

If you want to learn more about A/B testing, check out the below video from the cold email master himself, Vaibhav Namburi.


Dear reader, remember, there’s only one chance for the first impression in the cold emailing world. The prospect sees the subject, either click it or not, and that’s the end. You don’t get another chance to go and explain what you meant in the subject line. 

So, if you intend to stay away from the spam filter, I suggest you work on your subject lines with utmost priority. However, if it’s too much pressure for you, you can pick any of the above examples. But, I would suggest using an AI-driven tool to personalize the subject line using the prospect’s recent happenings. 


What should be avoided in the subject line?

In sales email subject lines, you should avoid using sales-y terms, pushy tone, making the recipient guilty, irrelevant emojis, misleading information, etc. to avoid spam folder. Some of the examples are:

  • Sales-y terms such as buy now, 10% off, last-minute deals, steal the deal, etc.
  • Pushy tone such as Open this email NOW
  • Making the prospect guilty by saying Why didn’t you check my last email? 

How do you grab attention in an email subject?

You can grab attention in an email subject line by referring to a competitor company’s name, an industry expert’s review, recent news or trend, or statistics. 

In addition to this, you can also try using personalized information such as a recent event in the prospect’s company, their achievement, etc. 

What words trigger spam? 

Words such as money back guarantee, get paid, 50% off, cash overflow, dollars, price, last-minute deals, big bucks, credit, debit, profit, etc. 

What’s a Rich Text element?

The rich text element allows you to create and format headings, paragraphs, blockquotes, images, and video all in one place instead of having to add and format them individually. Just double-click and easily create content.

  • dfbvrsg
  • svsv

Static and dynamic content editing

A rich text element can be used with static or dynamic content. For static content, just drop it into any page and begin editing. For dynamic content, add a rich text field to any collection and then connect a rich text element to that field in the settings panel. Voila!

How to customize formatting for each rich text

Headings, paragraphs, blockquotes, figures, images, and figure captions can all be styled after a class is added to the rich text element using the "When inside of" nested selector system.

Author’s Details

Rajnish Das

Rajnish Das is an in-house writer at SmartWriter and SmartLead. She writes product-oriented, data-driven content for B2B SaaS audiences and educates them on marketing and sales topics. Her expertise includes outbound marketing techniques like cold emailing and LinkedIn outreach.


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