34 Killer Cold Email Subject Line Examples for Guaranteed Response

Whether you’re in sales, recruitment, marketing, or any other field, there are always times when you need to reach out to strangers to help you achieve your goals.

To do that, you must know how to craft and send cold emails.

With over 4 billion people using email, it’s one of the easiest, safest, most affordable, and effective ways of connecting with people. Despite being one of the oldest forms of electronic communication, email marketing still gets some of the best results compared to other more modern techniques.

That’s why cold emails are a great way of reaching out and connecting to your prospects.

What is a cold email?

Before we dive into our killer cold email subject line examples, let’s quickly define what a cold email is. Simply put, a cold email is an email you send to a person you don’t know. The purpose of this is to get the recipient to help you achieve a goal. The goal can be anything from making a sale to building backlinks to your website to recruitment and everything in between.

The key to a great cold email is that it must propose a transaction beneficial to both the sender and receiver.

Contrary to popular belief, cold emails aren’t just reserved for sales. You can use them for many different purposes as their primary function is to connect you to people you can partner with for any kind of venture you’re working on.

What makes a great cold email?

One of the main reasons cold emailing has had a bad rep is that many people don’t know how to write a cold email.

Most cold emails suck.

And because they are poorly written, most get sent to the trash folder unopened.

So what makes for a great cold email that gets opened and read?

Here are a few elements you need to get right for your cold email to work:

A killer cold email subject line

This is what we’ll be talking about for this article, so hold onto your seats. However, a point to make here is that your subject line must be less than 60 characters in length. Longer than that and it gets truncated and loses its meaning and impact.

Personalized content

From using your prospect’s name to personalizing your offer, your email copy must be personalized to be on trend. To do this, you must research your target audience well.

A good pitch

The way you ask for whatever it is you want is crucial. You must do it in a way that isn’t too pushy or salesy.

An incentive

What will your recipient get from transacting with you? Offer them an incentive that is relevant and appealing to them.

A compelling call-to-action (CTA)

Your call to action is the statement that seals the deal. It’s the statement that you use to move the reader to take the next step.

Getting your cold email right is essential to ensuring good open and conversion rates. So take your time to know your prospects and craft an email that they’ll love.

34 best cold email subject line examples

Ready to get your next cold email campaign underway?

For you to enjoy good email open rates, you must nail the subject line. Your cold email subject line is the first thing your recipients see when your email lands in their inbox. Its main function is to encourage your recipients to open your email.

In essence, your cold email subject line determines whether your email will be opened or not. Your campaigns’ success depends on it. And that’s why you must take your time to come up with the best ones.  A few best practices to help you craft good subject lines include:

  • Personalization. Use the recipient’s name or a piece of information they relate to. Doing this will make it easier for them to connect to your email.
  • Keep your subject lines short. With most email opens happening on mobile devices, keeping your subject lines optimized for mobile is crucial.
  • Test your subject lines. Create several subject lines, and A/B test them to pick the one to use in your campaign. Also, test to see if your subject lines render correctly across all devices and platforms.
  • Leverage the preview text. The preview text is the short snippet of text right after the subject line. Use this section to give your subject line more context.
  • Segment your email list. Once you’ve compiled your email list, segment it by grouping similar prospects together. Doing so will aid in your automation and personalization efforts.

To help you craft your winning subject lines, let’s look at some of the best cold email subject line examples we’ve seen. We’ll also look at what makes them tick. This will help you gain insight into the best practices you can implement in your cold emails.

Short subject lines

Short subject lines are best for grabbing attention. That’s because they are punchy and get straight to the point. They can also be easily digested at a glance, allowing your recipient to quickly decide whether they want to open your email or not.

And if you craft your short cold email subject line well, you have better chances of your prospects opening it. Here some examples to inspire you:

I can help you [goal/aspiration].

This sales strategy rocks!

Question-based subject lines

Another type of cold email subject line you can use in your campaigns is the question-based subject line. For this type of subject line to work, your questions must:

  • Be relevant
  • Be provocative
  • Arouse curiosity

With these three ingredients in place, your subject line will result in readers opening the email to find out more. Here are a couple of examples of question-based subject lines:

Got a moment to talk about your career as a [career type]?

Tired of not meeting your goals?

Question-based emails also work well because the question implies the email contains a solution to a pain point. Of course, this will help drive your open rates up.

Personalized subject lines

People feel more comfortable interacting with things they’re familiar with. It’s basic human psychology.

And that’s the reason personalized cold email subject lines work so well.

Using the recipient’s name is the main way to personalize your subject line. However, with a bit of creativity, you can take personalization to the next level. All you have to do is infuse a familiar element or two in your subject line. This will make your recipient feel there’s a connection between you and them. As a result, they’ll feel safer opening your email.

And there’s data to back this up as research shows that personalized email subject lines can result in 50% higher open rates.  Personalized subject lines are also helpful as they help reduce spam complaints.

Need an example of a personalized cold email subject line?

Here are two to inspire you:

Remember me? We met at [event/place].

Hey [first name], interested in [offer/benefits of your offer].

The main aims of personalization are to grab your recipient’s attention and inspire trust. Doing so will ensure that your campaign succeeds as more people will open your email.

Humorous subject lines

Humor is (almost) a universal language — everyone loves a good laugh. And that’s why humorous subject lines are a great way to warm up your prospects.

Humor Example

Granted, you must be careful with this type of subject line as people have different tastes when it comes to humor. That’s why you must make sure your humor is tasteful.

Need some examples of tasteful humor used in cold email subject lines?

Wanna know what tearing my pants (on the subway) taught me about marketing?

The ’80s called, and they want their sales strategy back.

FOMO-fueled subject lines

It’s human nature not to want to miss out on anything. That’s why the fear of missing out (FOMO) can be an excellent cold email subject line ingredient. To pull this off, your subject line must:

  • Create a sense of urgency.
  • Leverage negative exclusivity.
  • Use language that triggers FOMO.

Sometimes all people need to take a step is a small nudge. And FOMO is one of the best ways to give your prospects that gentle nudge. Here are a few examples of FOMO in action:

Are you the only one who hasn’t heard?

Don’t be like Jake, who missed this [offer] last year.

Use your prospect’s base human nature to hook them and direct them to your offer. A point to note about using FOMO in your cold email subject lines is that you mustn’t overdo it. If you use it in the initial email, don’t use it in the follow-up. Doing so will diminish the value of the offer and the urgency.

Rock-the-boat subject lines

While taking the safe route is usually better when initiating contact with strangers, sometimes you must “rock the boat” to get them to pay attention. This is where rock-the-boat subject lines come in. These are subject lines that are a bit controversial, opinionated, or shocking. While you run the risk of alienating your audience, if you can craft your subject well, you’ll:

  • Make your email stand out.
  • Arouse curiosity.
  • Spark conversations with your prospects.

With so many emails hitting your prospects’ inbox, sometimes you must make a bold move and dare to be different. Rock the boat if need be. The worst that could happen is that they’ll ignore your email. However, if your cold email subject line succeeds to rock the boat in the right direction, you’ll enjoy good engagement rates.

So what do rock-the-boat email subject lines look like?

You’re wasting time and money on your design tools.

Do you really know where your marketing spend is effective?

This type of cold email subject line’s main thrust is to stop your prospects in their tracks. It must be so thought-provoking that it elicits a click.

Email subject lines for sales prospecting

Outbound sales prospecting is one of the main areas that cold emails are used. And because this is where most businesses generate a significant portion of their leads, the initial cold email must be crafted with care.

An element that must be treated with the utmost importance is, of course, the subject line.

Let’s look at a few cold email subject line examples you and your sales reps can use in your sales prospecting emails.

The value-focused subject line

The value-focused email subject line, as the name implies, is all about showing your recipient why they should open your email. It pitches the value they’ll get when they open your sales email. This is super important as studies show that the average person sends and receives an average of 126 business emails per day.

Average Number Emails received

With such a volume of emails in their inbox, your recipients will only open emails that add value to them. That’s why value-focused emails are excellent for driving open and conversion rates.

Let’s take a look at a couple of value-focused cold email subject line examples, shall we?

We helped Joe rank on page one of the SERPs. We can help you too.

Increase your remote team’s productivity with this fantastic tool.

[Product] can help your team save 12 hours a week.

If you can compress your email’s value into a catchy subject line, you’ll undoubtedly stand out in the crowded inboxes.

The referral/name dropping email subject line

If your product or service is good enough, chances are that happy customers or other people in your network will happily direct you to potential customers. When this happens, your salespeople must be prepared with a cold email sequence to pitch your product/services.

To ensure you don’t waste the golden opportunity your contacts have given you, you must make sure your cold email gets opened. Leverage the mutual connection you have and name drop in your subject line. Doing so gives you an excellent opportunity to gain your prospect’s trust.

Need an example of how you can do this?

Here are a few ideas to help you out:

[Name] suggested I reach out to you.

[Name] loved our product. He thinks you will too.

Using your mutual connection’s name will do all the heavy lifting for you. However, you must be sure your prospect will know who you’re talking about for this type of subject line to work. If you’re not sure they will, you can use the preview text to give more context.

The direct ask subject line

Sometimes the best way to get your cold email to be opened is by using a subject line that gets straight to the point. Some people appreciate this approach as it doesn’t waste their time. They know precisely what your email is about, and if they’re interested, they’ll click through. Here’s how the direct ask works in cold email subject lines:

Need help building your sales pipeline?

We’ve designed an ATS we think you need to try.

The trick with the direct ask is that you must either trigger a pain point your prospect has or highlight a benefit they will get from your product/service.

Curiosity invoking subject lines

Whether you’re in B2B or B2C, one thing is sure — your prospects are human beings.

What does that have to do with cold email subject lines?

Well, everything.

But one aspect of human nature I’d like to zero in on is curiosity. It’s one trait every human being has. And that’s why people fall for clickbait. Don’t get me wrong. I’m not an advocate for clickbaity subject lines. However, you can use the main ingredient of clickbait (curiosity) ethically in your subject lines. Take a look at these examples:

These are the tools giving [company/competitor] an edge.

Want to know the 3 things successful B2B buyers do?

For your curiosity invoking subject lines to work, they must not only appeal to your prospect’s sense of curiosity but must align with the message of your email. Failure to do so will leave your prospects feeling cheated into opening the email.

Data-driven sales prospecting subject lines

If there’s one thing that will grab your prospects’ attention, it’s data. People want to see evidence of what your product can do. And the best way to do that is to show them facts and data. And what better place to use that data than in your sales prospecting cold email subject line?

[Tool] helped [Company] increase their conversion rate by XX%.

Want to boost your ROI by XX%?

Data gives your prospects proof that you’re not all talk. It’s evidence that what you’re selling will deliver the results they’re looking for.

Follow-up email subject lines

Not everyone will respond to your cold email. Most personalized cold email campaigns average a response rate of 9%.


Average Reply Rate

It’s numbers like this that make many people shy away from cold emailing. But there’s a simple trick to pushing those figures up and getting better conversion rates as well.

That simple technique is following up.

And just like your initial cold email, your follow-up email campaign must have a well-crafted subject line if it’s to be effective.

“Do you have any questions about…?”

Have any questions about [topic addressed in the previous email]

One of the reasons this subject line works well is that it reminds the prospect about your first email. It also gives them a gentle nudge to interact with you by asking any questions they may have. This helps overcome any inhibitions they may have about your product.

“The offer still stands.”

This type of follow-up email works well if your initial email contained a special offer for your prospect.

Jim, your offer for 50 free leads still stands.

Any variation of this subject line works as it reminds your prospect that they can try out your product without making a significant commitment. Everyone loves freebies and special offers, so reinforcing the fact that you have one for your prospect. You can even add some more incentives to sweeten the deal and encourage a faster response.

“You don’t want to miss this.”

One of the best places to use FOMO is in a follow-up email.

Don’t be the guy who bought a pizza with $446 million worth of Bitcoin.

Hinting at a missed opportunity that will cost them a fortune down the road is a great way to inspire your prospects to open your follow-up email. After all, no one wants to be seen as the loser who messed up big time.

Here’s another example:

Are you in? We’re soon closing the doors on [offer].

Because time is running out, and your prospect will think twice about missing the opportunity you’re presenting.

The “double whammy” follow-up subject line

If a prospect doesn’t open your email the first time, you may have to be a bit radical the second time around. One way you can do that is by using the “double whammy” subject line. This is simply a subject line that appeals to two or more elements of human nature. Here’s an example:

I’m no Heisenberg, but the deal I cooked up for you will make you high.

The above example contains humor and triggers curiosity. Such subject lines, done well, have a “magnetic force” that compels the recipient to open the email — just to satisfy their curiosity.

But don’t stop at the subject line. Your email content must also continue on the same note. One way you can do that is by using personalized images in the email itself. Doing this will ensure your prospect remains engaged with your email, increasing the chances of them considering your offer.

6 professional email subject lines examples

As I said in the beginning, cold emails aren’t just reserved for sales. You can use cold emails to achieve different professional goals. And yes, the subject line still matters.

Let’s briefly look at a few professional email subject line examples used in settings that don’t involve selling.


Cold emails play a significant role in recruitment. It features on both ends of the spectrum — headhunting and applicants looking for employment opportunities. Here are a couple of examples of subject lines that work well in this vertical:

Heads up! [Company] is hiring, and I think you’re a good fit.

This could be the dream job you’ve been waiting for.


Other non-sales industries that leverage cold emails are those involved in research.

Research Example

Researchers need a large pool of subjects to get more empirically accurate results. This requires reaching out to people and organizations they’ve never interacted with before.

Would you like to help the [industry name] advance?

Can you spare 5 minutes to answer a few questions concerning [topic]?

Event Marketing

Want to ramp up the attendance for your next event (both live and online)?

Cold email can help you achieve that. And here are some cold email examples to help you in this particular niche:

[Speaker] will revolutionize [prospect’s company].

Last year was awesome. This year [event name] goes epic.

The key to event marketing subject lines is to make your prospects excited about attending. Name dropping certainly works, as by building anticipation.

Using personalized cold email templates

Because cold emailing involves sending emails to many different prospects, personalization may be daunting. To make it easier, use personalized cold email templates.

Fortunately, being a cold email, it doesn’t have to be hyper-personalized. You only need two main elements to create personalized cold emails:

  • Create templates for each target group/persona.
  • Research individual prospects and personalize an element of the email.

It’s on the second part that tools like Hyperise come in handy. They help you create personalized dynamic images for each prospect or business you’re reaching out to. Personalized images you can include in your cold emails include custom screenshots, company logos, your prospect’s profile photo, and other types of images.

Email example:

Email Example Personalized Email


Email Example Personalization Response

Armed with a cold email template for each of your target personas and some personalization tools, sending out cold emails becomes a matter of plug and play. Not forgetting your email service provider (ESP), of course, without which you can’t send automated campaigns.

A few tips to remember as you use cold email templates include:

  • Keep it simple. Don’t overcomplicate your template, as this creates more room for errors, particularly concerning personalization.
  • Research your prospects. Know your prospects and find out what their main pain points are. This will help you create cold email subject lines and messaging that’s relevant.

Cold email subject lines — way to warm up your prospects

Despite all the negative talk around cold email, it works. That’s especially if you take your time to create cold email subject lines that will move your prospects into engaging with your email.

Crafted well, your cold email subject lines will undoubtedly warm your prospects up to your offer.

Using the tips above, craft cold email subject lines that will stand out in your recipient’s crowded inbox. Remember, your subject line determines whether your email will be opened or not, so give it the love it deserves. If you have any comments or questions regarding cold email subject lines, feel free to drop them in the comment section below.