If your email is not opened, no one will read it. In a way, the subject line is one of the factors that will determine the success of your campaign.

In this article, you will find the 59 best subject lines I guarantee will bring fire to your cold emails and help you crush your next campaign.

What is a subject line in an email?

A subject line in an email is a single line of text your prospects will see when your email lands in their inbox. Quite often, this is the most important factor that will influence whether or not they'll open and read your email.

Why are email subject lines important?

As previously stated, the cold email subject line is key because it sets the expectation in your prospect's email on what to expect out of the email and aims to intrigue them to open it.

Think of you walking down the street and passing by a newsstand. A headline of a newspaper grabbed your attention, so you stop to take a look and end up reading the article until the end. The subject line has the same mission to accomplish for your campaign, hooking your leads so they start reading your email.

How long should an email subject line be?

An email subject line shouldn't be longer than 5-6 words. Meaning, it should be sharp, short, and exciting. The is because of the world's new favorite device - mobile.

This is how your subject lines for cold emails will look on Dekstop:

And this is how it's looking on your mobile:

As you can see, less real estate to play with. Word of advice, keep your subject lines sharp and make sure the most powerful words are mentioned at the beginning of your subject line.

What types of email subject lines get opened?

What makes a good email subject line? Well, before we jump into subject line examples for cold emails, let's go over some rules, truths, and myths about one of the important components of email outreach.

To understand how to write a good subject line, you first need to be in accordance with these few rules of the trade:

  • [type 1] Personalize your subject lines
  • [type 2] Intrigue your prospects
  • [type 3] Social proof and urgency
  • [type 4] A/B test subject lines

How to write email subject lines that get opened using psychological tactics

Let’s look a little more deeply into how to write email subject lines that get opened

[type 1] Personalize your subject lines

Typically, people add {{firstName}} or {{companyName}} tags to personalize their subject lines. That's good and it works.

If you want to take it step further, you can include tags such as {{painPoint}}, {{commonGround}} or {{Objective}}.

Just remember to keep it short and punchy.

[type 2] Intrigue your prospects

Back to my newsstand analogy from a few moments ago. To expand on it, sometimes I'd go to buy one magazine and end up purchasing three just because they caught my eye. If the content delivers once I read it, guess what magazine got another reader.

The objective is to incentivize prospects to want to know more. For instance, if you write a cold email subject line for a podcast host that goes -  "I've got a story for you", it's intriguing, right?

[type 3] Social proof and urgency

In my experience, these two subject line strategies perform the best when you have a brand behind your email domain.

However, they can work even if your company is in its early stage. For instance, mentioning how their competitor or a company they admire did something (e.g. How Notion grew 30% last year), might do the trick.

Plus, if it's your client, even better, as you will have all the details to showcase in the email.

The same applies to urgency, only you have to tie your offer to their need. It can't just be urgent or scarce, it has to be of value to your prospect first.

[type 4] A/B testing subject lines

Don't know if your audience prefers pizza or pasta. Let them try both. Send one subject line to 50% of your audience, and let the other half interact with the second version of your subject line.

subject line A/B test

As a general rule, you want to have 100-200 people in your email list, in order to make your split testing relevant.

Recommended read: A/B test tutorial.

59 best cold email subject line examples

In this section, we're going to talk about effective cold email subject line examples for different outreach objectives.

Whether that's for sales prospecting, B2B, networking, etc... doesn't matter. We'll list them all.

12 best email subject lines for sales prospecting

Coming up with a great subject line for your outbound sales campaigns can sometimes be challenging. Email is a crowded channel with too many salespeople lurking around.

But, we're not giving up as it's still one of the most efficient channels to grow your business. So let's talk about the best subject lines for sales.

Subject line: Question?

I think this subject line is like Michael Jackson's Thriller album. It will never get old. People use all kinds of variations like "Quick question" nowadays, but the original version was this one beautiful word with the sign at the end.

In combination with the right audience and a powerful brand behind your email domain, it's a killer subject line, even if it's overused these days. I got an 83% open rate.

Subject line: I think it's a match

The origin of this subject line is closely tied to our Tinder cold email template. A 75% open rate is the latest result from one of our users who leveraged this strategy.

Tinder cold email

It's ideal to use for prospects that you feel can be a great client or partner of yours. The subject line and the template leave enough room for you to be creative and demonstrate why it's a match.

Subject line: To {{companyName}} with ❤️

If you know anything about lemlist, then you know we're very much obsessed with emojis. For me, it's the same and a subject line is one of the key places where I use emojis a lot.

This example is my go-to subject line when I'm sending an email with a personalized video thumbnail. It has never let me down. Plus, if you've managed to build a powerful brand behind your company, the results are INSANE.

Subject line: For {{firstName}} the 💪

This subject line is a close relative to the previous one. Unlike when you use a {{companyName}}, here you're more focused on developing a relationship with the person instead.

My use case scenario is to leverage it after establishing the first contact on LinkedIn with the prospect. That way, they kinda know me already and the way I speak, so a subject line like this matches my personality and the email content.

Subject line: Something for you {{firstName}}

A more serious version of the previous subject line. It also performed really well in my own tests.

81% open rate...

This is an especially good subject line for businesses looking to sell products such as dropshipping entrepreneurs and eCommerce companies.

Subject line: love your growth {{firstName}}

With a 57% open rate score, the example here is from a friend of mine who used it to approach people working in the growth marketing department.

Subject line: Hit your {{Goal}} with [PRODUCT]

I've seen various variations of it on the web and I played with it in my own campaigns early on. There were moments when it worked perfectly (62% open rate), but also those when it underperformed.

My learning was that you have to nail the {{Goal}} tag. It really needs to be spot on for it to work, especially because it's quite a sales-y subject line.

Subject line: No {{firstName}} No Party

I'm a big fan of football... European football of course. A long time ago, Italy played awful at one championship and they didn't invite one of their stars to the team that year. It was Andrea Pirlo.

After Italy failed, Andrea came wearing "No Pirlo No Party" t-shirt. I laughed my eyes out and have been using this as a subject line in cold email and drip/onboarding campaigns forever.

{{firstName}} tag can be many different things, depending on your pitch. An average of 68% open rate.

Subject line: {{firstName}}, you’ll love this

The best usage of this subject line is when you know for a fact that someone needs a particular feature, product, or service.

And then you just deliver the great news in their inbox.

Subject line: {{Connection}} recommended I get in touch with you

Straightforward option if you're playing the referral card. {{Connection}} is the first word they see and that's quite important.

80%+ open rate...

Subject line: A better way to {{Objective}}

An interesting angle through which you can identify a pain point and propose a solution.

Mind the rule. Don't talk about features, focus on how you solve their pain.

Subject line: We are losing you {{coolName}}

This is an idea from a colleague of mine that was used on another lempire's project, scoring some nice conversions and reducing churn.

{{coolName}} tag can be replaced with a "nickname" for your product user. For example, we call people who use lemlist - lemlisters.

Recommended: Cold email marketing guide


8 best B2B subject lines

When it comes to B2B sales email subject lines, things can become a bit broader than just sales, because there are quite a few ways to drive revenue these days.

Here are several examples that worked well for our team and our users too.

Subject line: Intro

One of the simplest subject lines I've seen and it's coming from Benoît D'koko from Groowster, a user of ours.

He's scoring an average of 80% open rate with this line which is pretty amazing.

Subject line: Hey {{firstName}}, congrats on your funding round

Personally, I've never used this one, but I've talked to a bunch of salespeople who're playing with it frequently.

Essentially, when a startup raises a round, it sends a few signals. Depending on their business model they can, for example, use the funds to expand their sales team. And if you have a product for sales teams, that's a good fit.

The results range across different people who are sending cold emails and their quality, but it's fair to say it's between 40 and 60% open rate.

Subject line: How {{Competitor}} gains {{Advantage}}

A very interesting way to grab your competitive prospect's attention. Somebody I know uses this really well.

Especially if you can turn the {{Advantage}} tag into something meaningful that will strike a chord in your prospect's head.

Subject line: Let's meet at SaaStock {{firstName}}

The subject line I used when I went to the SaaStock conference in Dublin 2019.

Not much explanation needed for this one. Focus on writing a personalized cold email and just copy/paste the subject line. Maybe add a beer emoji in there like I did for Dublin. :)

Subject line: Introducing [Product] - franchise opportunity in {{country}}

Another subject line from one of our lemlisters of the week that scored a 91% open rate.

lemlister of the week

It's super specific and not everybody can just copy/paste it, but you can use the winning formula behind it. It's sales-y, but it smells like a win-win if the audience targeting is right. It got an 82% open rate.

Subject line: Build {{companyName}} like {{commonInterest}}

A perfect subject line if you've been able to identify a common interest between you and your prospect.

It can be anything from your favorite entrepreneur to a sports team, you just have to make sure it's relevant and it makes sense.

Subject line: # ideas for {{painPoint}}

Another cold email subject line classic. It calls for in-depth research prior to sending your campaign to understand different pain points.

The thing I hate when people pitch me using this subject line is when they give me a broad pain point, like "increasing revenue". Go narrow and come up with something more relevant and creative.

Subject line: {{companyName}} & [Product] integration?

Many startups and SaaS businesses as one of their growth strategies leverage partnerships and integrations.

If you're reaching out to suggest one of these possibilities, try out this subject line. It's simple and effective.

Recommended: How to start a cold email


18 networking email subject line examples

Without a doubt, one of the most fun cold email outreach campaigns to do. Figuring out what networking email subject line examples work best for your business is exciting, trust me.

Why? It's diverse and there are many objectives you can aim for.  :)

Subject line: Lunch?

A brilliant subject line example from Guillaume, our CEO. I was in our Paris office when he was preparing this campaign. Got a 96% open rate with it.

The goal? Meet with people working in Marketing & Growth, in top startups in Paris.

Subject line: Exclusive invite {{firstName}}

Building a community? Organizing an event? Or a webinar?

I love this subject line and it has a great response - 87% open rate.

Subject line: Interview invite

This subject line I've used to invite sales and growth experts to join our live webinars.

It's proven to be the best variation bringing me a nice 84% open rate.

Subject line: I've got a story for you

If you're trying to get your or somebody from your team featured on a podcast or a show, I found this subject line to be the bomb. It brought an 84% open rate as well as the previous one.

It's not mine, but I'm going to modify a quote from Pablo Picasso... "Great artists borrow!"

Subject line: Invitation for {{firstName}}

Many of us are actively using this subject line to build communities, grow beta signups, and for many other targets. The last open rate I've seen is 90%.

Subject line: love your work {{firstName}}

Will Cannon from Uplead and his team use this subject line to get founder interviews for their blog. It has a nice 80% open rate.

With a solid 80% open rate score, it's a perfect subject line for networking email. It's usually used to ask for a favor, exchange a backlink, or simply connect with someone.

Subject line: Business Partnership: {{companyName}} and [Your Company]

The example you're seeing is from another lemlister of the week.

lemlist of the week

A great campaign and a fantastic 82% open rate on the scoreboard.

Subject line: Closed group for marketers

It's the choice of mine while I was building the Game of Content community on LinkedIn.

It didn't perform spectacularly having got a 55% open rate, but it's not too shabby either.

Subject line: Invite-only Marketing Pod is on the rise... wanna join?

One more variation used to grow the Game of Content group. The open rate was 52%.

Subject line: Cold email guide from [Your Name]

The next from examples of subject lines you'll see are from Ilya Azovtsev, one of the fierce members of lemlist's growth marketing team.

He used this one to send a cold email guide to people who have submitted a form for early access and got a 65% open rate.

Subject line: Invite-only Growth Hacking community

Ilya also inherited a Facebook group for LinkedIn Growth Hackers and managed to grow it like crazy.

The subject line here was used for an email invitation to the group, bringing a 63% open rate.

Subject line: Invitation to the closed group for growth marketers

But later down the road, he updated the previous subject line with this one, which in turn has scored an 87% open rate, completely outperforming its predecessor.

Subject line: LinkedIn connection

Being a person who lives and breathes LinkedIn, Ilya decided to test lemlist and Phantombuster integration to automatically connect with key people on LinkedIn and later send them a cold email.

"LinkedIn connection" subject line got him a 72% open rate.

Subject line: Really like {{companyName}}’s SMM

This subject line was used to reach out to Social Media Marketing specialists and resulted in a 57% open rate.

Subject line: LinkedIn group

Being a growth marketer, Ilya started joining groups on LinkedIn to achieve different outcomes. He often sends cold emails to group members, so he decided to test this subject line and it paid off - 81% open rate.

Subject line: Liked your post on LinkedIn

Whenever somebody likes a post on Ilya's LinkedIn profile, he uses cold emails to reach out and establish a more close connection.

88% open rate shows it was a job well done.

Subject line: Fan of your LinkedIn

A subject line variation used to reach out to various LinkedIn experts and trainers that brought a 63% open rate.

Subject line: Liked your #recruitment content on LinkedIn

While building his connections in the recruiting world, Ilya leveraged this campaign to reached out to everyone who published posts about recruitment on LinkedIn.

Open rate? It's 82%.

Recommended: Cold email templates hub


2 recruiting email subject lines

Note: This may well not rank on this page, but we can try it seeing as the content is already in place. If not, another post targeting “recruiting email subject lines” may be a possibility.

Subject line: [Your Company] wants you {{firstName}}

I've always been a big advocate of approaching people to join your team, if you feel they are the right choice.

When recruiting, you want your subject line to tell the point straight. This variation has never let me down, scoring an average of 70% open rate in the way.

Subject line: We're looking for a {{jobPosition}}

My second variation, kind of a substitute for the first variation above.

Similar open rate score, with the average in the "sixties", it's another example of a clear and straightforward cold email to follow.


Bonus: 3 catchy email subject lines examples (great for standing out)

Some additional inspiration for you...

Subject line: We love {{Tool}} at lemlist

It's a great way to show respect and state your intentions in a catchy way.

Subject line: Happy to connect on LinkedIn

After you establish a connection on LinkedIn, this works pretty well.

Subject line: you inspired us to reach $5M

Another way of showing respect and making the subject line about your prospect.


Bonus 2: 2 funny subject lines (good for breaking the ice)

I'm a big movie guy, it's no secret. With that said, you won't be surprised with my funny subject lines.

Subject line: {{lastName}}. {{firstName}} {{lastName}}

Never gets old to play the James Bond card. Plus, you can tweak it and add a word or two after the name.

Subject line: Fasten your seatbelt, it's one good email

A modified movie quote version. In my mind, a mix of funny and intriguing.


14 example ideas for a follow up email subject line

Wondering how to subject a follow up email? You have two choices.

First, you can keep the same subject line as your previous email if the follow up is a part of a sequence. This is what usually happens and what I prefer to do in most cases.

On the flip side, when you're following up after a specific event, you don't have the first email that you can reference. In this case, it's your subject line that does that for you.

5 best sales follow up email subject lines

When it comes to follow up email subject line for sales, you usually tend to use those after you meet a prospect.

Subject line: As promised

My favorite follow-up subject line. It's usually used after a meeting or when I already exchanged a few messages with someone.

Whatever is that we agreed upon earlier, my follow-up is coming super fast and this subject line usually has some emoji at the end.

Subject line: Next steps 👊

This is an ideal subject line after you've finished a sales meeting or a demo. In the first phase of lemlist's growth, I was involved a lot in demos.

Both my open and conversion rates were solid. I'd wrap up a meeting, see if the deal has potential and the follow-up is coming in less than 30-45 minutes. A 70% open rates on average.

Subject line: Call recap

Another example you can use after sales meetings. Don't have open rate proof for this one, but I saw that many people use it online and I think it's good.

Subject line: Here's the info I promised you

A more formal way of my previous variation. It's good, straight to the point, and will probably get you a high open rate.

Subject line: It was nice to meet you

The subject line that scored a 53% open rate, mostly used after you meet someone at a conference.


2 B2B follow up subject lines examples

Similar to the previous section, B2B email marketing subject lines I've used in the past is usually when I got the conversation going on a conference or on LinkedIn.

Not longer after that happens, I reach out with these two subject lines, since they already know me.

Subject line: I had this idea since we last spoke

I noticed some salespeople like to use this when a lead is slipping away. Might be worth giving it a shot.

Subject line: From one growth marketer to another

Received an average of 55% for this open rate on a few occasions. In most cases, it had a B2B sales objective.


7 networking follow up email subject line ideas

It's the perfect time to talk about a few networking follow up subject lines.

Subject line: 🔥 tactics coming your way {{firstName}}

As a growth manager, you deliver a lot of links. To potential customers, for backlink exchanges, or to drive some awareness.

This subject line requires one thing to work. Someone asks about something on a call and you're not able to show it straight away for some reason, deliver it via email with this subject line... 91% open rate.

Subject line: Collaborate?

Another cold email subject line classic, used in thousands of ways. Usually, it brought me an open rate average of 50-60%. It can be used to achieve various outcomes.

Subject line: Wanna contribute to your Article {{firstName}}

A backlink cold email template. A standard of 75% open rate in 3-4 campaigns where I've used it.

Subject line: Love your YT channel... have an idea

I've used this subject line for a campaign to get in touch with some YouTube creators... a 62% open rate.

Subject line: Loved your articled about LinkedIn tools

This subject line is one of Ilya's favorites for SEO backlink outreach. It got him a 73% open rate.

Subject line: You are featured in the post on {{topic}}

A solid strategy to get your article shared more is to mention somebody (person, company, or a tool), give them a backlink, and reach out to let them know.

Subject line: We want to feature you on [Your Website]

An idea if you're looking for content reinforcements for the upcoming article.


FAQs

What types of email subject lines are prohibited by the can-spam act?

CAN-SPAM act is much bigger than subject lines. But, you should avoid using things like: CAPS LOCK (e.g. WIN or FREE), mislead your audience, use subject lines that are unrelated to your email content, etc.

Should I use a cold email subject line generator?

There are online tools that can write subject lines for you based on some input. I never used them. They don't have emotional intelligence. They don't know your brand nor your prospects.


Key takeaways

I hope these examples were inspiring and that will help you get some great open and reply rate scores.

Remember, a good open rate is just a checkpoint. You need those replies and conversions to get things moving, so make sure to analyze your subject lines against that as well.