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(Just) 5 Examples of Cold Email Subject Lines You’ll Ever Need

Cold Email Subject Line

When it comes to cold emailing, there’s one thing that can make or break your success—the subject line. 

We’ve heard this so many times. 

That, in order to get great email open rates, there’s a secret best cold email subject line that needs to be unlocked, and voila, you’ll 10x your leads. 

That’s why we’re enamored with the titles “70 Sales Email Subject Lines That Get Read” or even “136 Best Cold Email Subject Lines”. Maybe in one of those articles, we’ll find that slam dunk subject line.

What’s more likely to happen is: you test all these subject lines and then see similarly low results for each one. And you’ve burnt out your audience doing it. 

Then you realize that you could have gotten better ROI optimizing more impactful parts of the email campaign.  

While subject lines, especially sales email subject lines, are important, I’m guessing that most of you reading this blog already know to avoid writing ones like this: 

Cold Email Subject Line

At the end of the day, we have to remember that a good subject line is just a tactic. 

And what really makes cold email campaigns successful is the offer of the campaign itself. 

Looking back at that example again, why am I not interested in Rose’s email? Is it really the subject line that caused her campaign not to resonate with me? Maybe it contributed, but ultimately, it’s the spammy nature of her entire copy.

If her email copy were spot on, I would have completely forgotten about the terrible subject line and taken action. 

So, in this article, I’ll share the role of the subject line in your cold email campaigns, provide a few solid cold email subject line examples I’ve seen or used successfully, and illuminate some strategic tips to optimize your entire cold email campaign. 

What’s the Role of the Cold Email Subject Line

Your subject line plays one primary role: to get your prospect to open the email. 

That’s it.

You can increase the chances of this happening by creating some sort of open loop or curiosity-inducing factor.

In order to do this, you’d need to think of ways to stand out from a sea of emails in your prospect’s inbox. I like to look at my own inbox and make myself the prospect. 

  • What were emails that other people sent me that I’ve been curious enough to open?
  • Were there emails in the promotions or spam folder that I’ve moved to the primary folder?
  • What emails did I keep as new in my inbox to read later because I was too busy?
  • What factors made me pause? 

Collecting this information will give you a great mindset when you launch that outbound marketing campaign. After all, when you’re working in the backend of your email marketing tool, you want to remember your email will land in a real person’s inbox. 

6 Reasons Your Emails Aren’t Getting Opened That Have Nothing to Do with Subject Line

Even after this thoughtfulness, you still won’t get a 100% open rate.

While there may be room to optimize, at a certain point, you’ll need to remember that there are countless reasons why emails aren’t being read.

Because these factors also impact your open rates, you could have a killer subject line but a lukewarm campaign. 

So, what are some of these reasons? 

They are marked as spam

This is an obvious one and you never want to be here. To avoid the spam folder scan through this list of spam trigger words compiled by HubSpot and avoid them in your email copy. You’ll need to get through the spam filters and be able to reach the low hanging fruit reader like myself. 

They landed in the promotions/social folder

While ReturnPath’s study shows that 45% of Gmail users do check the promotions tab once a day, almost 20% never checked it. Your prospect may have been one of the 20%. Avoid adding too many links to your email content, use standard formatting, and drip out your emails.

They’re landing in the wrong inboxes

Most simply, you could have sent the email to the wrong person, or even worse, the person you are trying to email is no longer with the company. Try selling your SaaS product to a marketing coordinator or pitching a guest post to the VP of engineering. You need to do better contact prospecting and use an email verifier to make sure the email you’ll be using is valid.

They landed at an extremely busy time

The email falls during a time when the recipient is extremely busy and your email is buried by other emails. To optimize for this, you’ll need to know your industry’s best time to send cold emails or do your own A/B testing in order to discover this. 

Your prospect opens much later than you expect 

Your prospect could be saving your email for later. Sometimes I get a follow up email from cold outreach marketers after not responding for just 1-2 days. This can get annoying, leading to worse results for the sender’s campaign. As a busy in-house marketer, it can take me up to 5-10 business days to follow up so sending more emails doesn’t really help. Additionally, constantly refreshing the thread doesn’t work on me as I like to start reading from the oldest email, meaning that your new email just refreshed the thread and put it at the end of the stack.

Your sender name or picture is off-putting

Sometimes the name assigned to your email account hasn’t been set up properly and the prospect might mistake you for spam. Remember to add a profile photo of yourself to increase the chances of not being ignored. 

So, What are Ingredients of the Best Subject Lines for Cold Email?

Since there’s no such thing as a “best cold email subject line”, we can still analyze the ingredients that make certain ones more or less successful.

My experience with cold emailing primarily comes from running many partnership campaigns and lead gen campaigns. In these instances, my lists never exceeded 500 prospects, with a typical email list comprising 100-150 contacts (usually 2-3 targeted contacts from 30-50 companies). If you’re running massive campaigns designed to hit thousands, these takeaways may not be for you. I suspect, though, these ingredients will still hold true for the mass outreach. 

So, what are these key ingredients? The best cold email subject lines:

  • Are short and intriguing
  • Speak the language of the prospect
  • Engage the curiosity of the recipient

As you’ll see in the next section, not every effective subject line needs to score highly on all 3 categories, but if you can have all three ingredients, you’ll increase your likelihood of your prospect opening the email.

I’ll demonstrate what I mean by grading each cold email subject line type on these three ingredients. 

5 Types of Cold Email Subject Lines (with 14 Real Samples)

Rather than listing out examples separately, I’ll bucket these samples into groups.   

The introduction

The introduction or referral is an email subject line where you reference a mutual third party connection. This is by far the best way to get your cold email opened, as there is shared familiarity. You might argue that this is technically not a “cold” tactic. My response? Get creative with finding mutual connections or reference points. 

Here are some ideas of subject lines employing this type:

  1. Via [Name]
  2. [Name] told me to reach out
  3. From [Mutual Community]

Total Potential: High

Short and Intriguing: High

Language of prospect: Relevant

Curiosity factor: Medium

Scaling Difficulty: Medium

The reason this cold email template works is obvious. But, getting this opportunity requires a high level of personalization and experience in the field to be able to speak a similar jargon. Once you realize this is the fastest way to open doors, you’ll be all-in on the tactic. 

I used this subject line mentality in nearly all cold introductions while I was a musician – the music industry relies heavily on networking and connections. When I pivoted to SaaS, this type of cold email netted me opportunities with Calendly, ActiveCampaign & HubSpot. 

The question

The question is a very common type of cold email subject line that works. You create some intrigue with this open loop.

Some easy subject lines for this style of cold email include:

  1. Podcast?
  2. Open to this?
  3. Partnership?

Total Potential: High

Short and intriguing: High

Language of prospect: Generally Relevant

Curiosity factor: Medium

Scaling Difficulty: Easy

Not much needs to be said about this evergreen type of cold email subject line. It’s human nature to answer if you’re asked something. If you ask the right question, you’ll do very well.

The personalization

This subject line is where you know only the prospect would understand it. Some subject line examples for this style of cold email include:

  1. Your article in Venture Beat
  2. Mentioned you on Semrush

Total Potential: Medium

Short and intriguing: High

Language of prospect: Extremely Relevant

Curiosity factor: High

Scaling Difficulty: Hard

This personalized email is definitely one of the more challenging email subject lines to scale, especially if you’re trying to reach a wide net. However, the personalized subject lines will play on your prospect’s ego and pique their interests, so you’ll likely get a higher open rate. 

When I wrote a case study for Semrush, I used the second subject line “Mentioned you on Semrush” to start working with a few high quality partners, including content marketers from Screaming Frog and Sprout Social. 

The straight shooter

This straightforward method is where you include your ask in the subject line. 

Examples of this include:

  1. [Our company] <> [Your company] meet
  2. Let’s collaborate, [prospect’s name]
  3. Content strategy for [company name]?

Total Potential: Medium

Short and intriguing: Medium

Language of prospect: Generally Relevant

Curiosity factor: Low

Scaling Difficulty: Easy

While it may seem boring, this method will get you solid results and is a safe play if you’re launching your first campaigns and offers. 

You can see in the third example, “Content strategy for [Your company]?” is a hybrid of the question-type and the straightforward type and thus induces a slight bit more curiosity. 

Additionally, using the recipient’s name in the second example, “Let’s collaborate, [prospect’s name]” can definitely get your prospect’s attention. 

The “out of left field”

This type of cold email subject line will require some creative juice. The primary motive is to create a contrarian or unexpected subject line.

Examples include:

  1. [Our company] loooves [your company]
  2. Could this be the portkey to our collaboration?
  3. 1 link equals 10 trees

Total Potential: Medium-High

Short and intriguing: Medium

Language of prospect: Risky

Curiosity factor: High

Scaling Difficulty: Medium

Before you write these off as cringe or clickbait, remember the role of the subject line is to get people to open. As long as there’s some connection between the subject and your email body or some way to resonate with your prospects, you should have success. 

For example, I’ve used the first example, “[Our company] loooves [your company]” countless times, which is a play on the “[Company] <> [Company] meet” subject line, and it performs wonderfully (~70% open rates). However, I also have a reason for using it, as I only send this type of email if we recently featured the prospect company in some way.

While this subject line can get your prospect’s attention, using this cold email template can be risky for your brand perception. Before employing it, make sure you know your audience well, especially if making a joke or a reference.

Further Thoughts to Optimize Your Cold Email Campaigns

We have to remember that the subject line occupies a limited role in your overall campaign. While it is an impactful part of your cold email campaign, my advice is to test a few and find a couple of working ones that you use consistently. Then, focus your optimization efforts on more impactful elements:

  • Could you improve your offer to address your prospect’s pain point to improve response rates?
  • Is there anything you say in your email copy that causes resistance to action?
  • Are you using a good email finder to grab active email addresses?
  • Are you sending the emails to the right people?
  • Does your offer create a sense of urgency and are you sending them at the right times?

I’ve personally run over 30 campaigns and overseen 50+ other campaigns, totalling over 7,000 emails sent over the past year. Through these campaigns, I’ve successfully connected with hundreds of leads and maintained over 50% open rates. Could I further optimize my results by testing more subject lines? 

Yes. For me, finding a new subject line that works better in a statistically significant way is not worth the effort that could be better spent on launching and personalizing more campaigns. 

The Takeaway

Writing a great subject line takes practice, but you can use certain frameworks and tips to help you craft some great cold email subject lines that stand out from the crowd. Knowing the context and role of this tactic should help eliminate this as being a daunting task. 

If you’re a marketer looking for link or guest posting opportunities, check out our handy outreach email templates that’s proven to convert. It contains different subject lines, email copy and ideas for you to try out in your cold email outreach.

Hopefully with these examples at your disposal, you’ll be able to create unique yet engaging cold emails that keep people interested and excited about learning more about your product, service or collaborative proposal. So get out there and start sending those emails! You never know who might just bite!


Content Strategy