Getting the best subject lines for cold email is the difference between having your message seen and not seen.

It’s literally as simple as that.

Writing cold emails is hard enough, right?

But what if all your effort is wasted because people aren’t even opening your emails?

Many people think of the subject line as an afterthought.


Nobody will click through to your website if they aren’t first opening the email.

What the Experts Say about Cold Email Subject Lines

The question of cold email subject lines is something that every B2B sales rep and business owner has had to deal with at some point.

Several business owners have laid out their experiences and advice across the web.

Here’s the thing: it’s different for everyone. What works for me may not work for you.

With that said, here are some best practices to consider when writing your subject line.

Context is incredibly important when it comes to what works.

For instance, at the LeadFuze office, we’ve found that a less personalized subject line has worked better than one that has even the company name in the subject.

This is especially true for an introduction email subject line. You do not want to highlight the fact that you do not know each other.

Now, we are always a/b testing cold emails though, so this is far from a finalized statement. 

But if you’re coming from a local business meeting, you may want a highly personalized networking email subject line.

Something like, It was nice to meet you at [XYZ event] Mr. Smith.

Having said that, the tips today will be relatively useful to all. But remember to test everything and keep what works.

Test everything and keep what works. What works for me may not work for you. Click To Tweet

Editors Note:

Now, I’m going to assume you already have a fresh clean list of leads to reach out to with your cold emails. If not, this is for you…

LeadFuze is a software solution that helps you build lists of accurate leads automatically, while integrating with sales outreach tools to allow you to contact those freshly verified leads.

subject lines for cold email

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Now, lets move on to actually contacting those leads. 

My weapon of choice is cold email. So, let’s get into some very simple, yet very critical tips for your cold email subject line.subject line for cold email

Cold Email Subject Line Tip #1: Keep It Short

Most email clients truncate subject lines after a certain number of characters, but if you’re anything like me, you don’t even read all the characters that are shown.

Why would your prospects be any different?

Keep your subject line as short as possible.

Bryan Harris at Videofruit recommends 3 words or less.

Takeaway: Shorter is better.

Cold Email Subject Line Tip #2: Keep It Real

Most people send out cold emails that are so obviously marketing, it’s a wonder anyone opens them.

Don’t be that guy.

Templates and other tricks for speed are fine, just make sure the email templates are quality.

If you wonder if it sounds too much like a ‘marketing email’ then it does sound too much like a marketing email” – Steli Efti,

Cold Email Subject Line: marketing email

One thing that can help make an email look human is actually the lack of capitalized words.

Think about it.

If you’re writing a quick email to a friend, do you take the time to capitalize the subject? Probably not.

Takeaway: Write your subject line like you are writing an email to someone you actually know.

Cold Email Subject Line Tip #3 : Keep It Personal

Before you email someone, you should have at least done enough research on the company to get the name of the person you are emailing.

You may have even come across someone in your network who knows the prospect and can help give you a warm referral.

Takeaway: Use your prospects name or company in the subject line if it makes sense.

Cold Email Subject Line Tip #4: Keep It Relevant

No one likes to be tricked into opening email (or snail mail) that looks like one thing and turns out to be another.

Make sure your subject line is appealing, but relevant to the content of the email.

Takeaway: Don’t bait and switch your prospect.

Cold Email Subject Line Tip #5: Keep It Genuine

Ok, so this last tip isn’t directly related to the subject line itself.

That said, it’s incredibly important that you live up to your incredible subject line.

There are so many one-liners and hacks online that, sure, they’ll get people to open up your message.

But when they see it’s just a cold pitch to your company’s products/services—it’s like they never opened it.

Let’s say you met someone at an event and you used our networking email subject line to peak their curiosity.

What if they went into the email and found a warm genuine compliment along with a resource that you thought the person might enjoy?

Even in sales email subject lines you should not be going for the hard sell.

Rather try to be genuinely helpful by giving a resource. (Either one you’ve created or from another source.)

We’d put that up against a cold pitch any day of the week.

Takeaway: Make sure to genuinely reach out and offer value

Email Subject Line Examples

If you are stuck on coming up with good email subject lines, Steli recommends trying the following variations:

  • “Introduction: {Name}” or “Introduction {your name/company} <> {their name/company}
  • “quick request”
  • “Trying to connect”
  • “{name of their company}”

I am not a fan as much of the first one since it’s more of an introduction email subject line. However, he has had success with it.

One of the best email subject lines for sales purposes that I have found is:

  • “Partner?”

Steli also recommends trying questions in the subject line and making it as specific as possible.

Bryan similarly recommends using the company name along with a very short description of what’s inside the email.

Subject best practice: Use the company name along with a very short description. Click To Tweet

From my end, I have seen good success with simple subject lines such as “quick question” as well (i.e. a short description of my service) though this one is a little more played out now.

Snippets: The Extended Subject Line for Cold Email

An often overlooked part of the subject line for cold email is the snippet. A snippet is the short length of text that is shown as a preview of the email content.

Cold Email Subject Line

When you are working on your cold emails, be sure to think about what your snippet might look like.

Encourage your prospects to open the email by making it feel like it could be coming from a customer.

The start of the email is another place to personalize the email and to show your prospect that you have done your homework, without being creepy.

Open the email with a casual salutation, and use the prospect’s first name if you have it.

Follow best practices

There’s a lot of innate variability in effective email subject lines, because every fresh context will bring unique challenges. That said, there are some broad best practices that apply in almost all scenarios: you can read about some of them here.

They consider things like subject line length, relevancy, and the offered value, and you should follow them unless you have a compelling reason to do otherwise (just as writers should mostly adhere to grammatical standards).

Personalization is an interesting point, because the option of including someone’s first name in the subject line is inconsistently useful (sometimes it catches the eye, and sometimes it comes across as annoyingly presumptuous), but you should always write as though you know the recipient.

Stylistic personalization — understanding your audience and shaping your phrasing accordingly — is essential.

Never settle for a generic approach when sales are on the line.

Never settle for a generic approach when sales are on the line. Click To Tweet

Draw from clickbait tactics

You might not like clickbait, but it’s effective — and provided you can actually back up what you promise (i.e. there’s message match between your subject line and the content of your email), there’s nothing wrong with using it.

SEO guru Stephan Spencer has a good breakdown of tactics used in Buzzfeed headlines: all of which illustrate various tricks proven to be incredibly potent.

One that I think can be used to particularly great effect is the classic curiosity construction.

Here’s one possible example: “ Our average customer saves how much?!”

The implication that the answer is shocking even to the sender is a potent hook, and the recipient might want to open it up just to see how surprising that figure is. And once they have the email open, they can be reached by whatever marketing message is most appropriate.

You can also run with mild controversy by getting contentious. “ You’re 100% wrong about [product].

Here’s why: ” has a lot of potential, because it plays upon two aspects of the human condition: the curiosity we just looked at (“What did I get wrong?”) and the ego (“Oh yeah? I’m 100% wrong? I don’t believe you. Prove it.”).

Don’t get too controversial — for instance, stay away from politics if you value your brand — and you should be fine.

Use the reliable fear of missing out

Overcoming the “I’ll just leave this for later” email reaction is tough, but one tactic that usually proves effective is leaning on the fear of missing out (usually shortened to FOMO, such is its ubiquity).

FOMO encompasses everything from offering timed discounts or limited-edition sales to detailing how popular your product is with other customers. If you can make the reader worry about being left out of something great, you can prompt a quick reaction.

Note: Your cited limitations don’t need to be entirely legitimate, and if you’re concerned about that, you can stick to vagaries: this is precisely why you’ll see messages like “It’ll be gone when it’s gone” (true by definition in all cases) and “Stock is selling quickly” (implying that a limit is being neared, but not explicitly stating it).

Doing Your Own Experiments

It will take some experimenting to find the best subject line for cold email that will work for you.

Even when you find a subject that’s working, remember your ABT’s — Always Be Testing.

It will take some experimenting to find the best subject line for your cold emails. Click To Tweet

When you are first getting started with cold emails, you should try vastly different subject lines to get an idea of what direction you should go.

Once you have some initial data, you can start refining a single type of subject line.

Experiment with emojis

Regardless of your personal opinions about their use, the social media age has made emojis iconic (please excuse the pun) — to the extent that they’re commonly used in everything from formal emails to business pitches.

In a time of incredible product and service accessibility, the market leaders are increasingly the brands that excel at connecting with people. This requires showing personality, emotion, and playfulness, making emojis perfect fits.

Consider, though, that this isn’t a targeted recommendation.

It’s just a matter of expanding your vocabulary and understanding that some simple imagery can do wonders for enhancing, clarifying and contextualizing your subject line copy.

I’m on the Phrasee mailing list (it’s a company that uses machine learning to generate effective subject lines and email copy), and almost every email I receive ends in an emoji. It works .

Iterate using feedback

Regardless of the methods you end up trying, the most important thing is that you commit to continually testing (and subsequently adjusting) your subject lines.

Language is incredibly broad, particularly with emojis thrown into the mix, and people are complicated — you’ll never quite know which of any two variants will work better, so A/B testing is essential.

Remember the ABT mantra: Always Be Testing, no matter how effective your subject lines become, because there’s no such thing as perfection (if you did manage to hit a 100% conversion rate, you’d have narrowed your audience down to a counterproductive extent).

Getting input from your prospects can be invaluable at this point.

As you are sending your sales emails, think about touching base with your current clients, as well as any prospects who respond to your cold emails.

Try to find out what about your email made them open and respond.

Some questions to consider are:

  • Why did you open this email?
  • What did you expect to find inside?
  • What made you respond?
  • Why did you feel this email was relevant to you?
  • Why didn’t you just delete or archive it?

By getting the answers to these questions, you can craft better, more relevant subject lines and copy for your cold emails.

Cold Email Subject Line Conclusion

We have more on follow-up subject lines follow-up subject subject lines. It’s important not to let your subject line kill your cold email.

Experiment with different types of subjects and refine once you have some data.

Start with some tried-and-true subjects that others have found success with, but don’t be afraid to create your own variations.

The cold email subject lines that work best for your outreach will vary depending on your business and your prospects.

By continuously testing, you can make incremental improvements in your open and response rates.

Editors Note:

Want to help contribute to future articles? Have data-backed and tactical advice to share? I’d love to hear from you!

We have over 60,000 monthly readers that would love to see it! Connect with me on LinkedIn and let's discuss.

Josh Slone
About Author: Josh Slone
Josh Slone is the Head Content Writer for LeadFuze. Josh writes about lead generation strategies, sales skills, and sales terminology.