Email subject line formulas help you get people to open, read, and take action after receiving one of your emails.
Looking for email subject lines that work? Maybe you’re:
- A marketing team emailing a limited-time offer to your list.
- A sales professional following up with a prospect.
- A support or customer service representative solving a problem for a customer.
- A recruiter reaching out to a talented candidate.
- A job hunter making connections with potential future employers.
- An employee asking for approval to move forward with a project.
Whatever your situation, many, many, many of us need people to open and read our emails in order to be successful.
We’re no different here at cloudHQ.
As a company that creates email productivity products, we spend more time than most talking back and forth with email messages.
Here are the subject line formulas we use all the time in our own work—and find very effective.
1: Curiosity
The curiosity email subject line formula:
If you tease someone with just enough information in the subject line, it’s very difficult to resist opening the email to see what’s actually happening.
Here’s how to make people curious:
- Make a promise
- Ask an interesting question
- Write something weird or different–something unlike anything else they’ll see in their inbox that day.
- Anything that gets people wondering: “What’s going on here?”
Curiosity email subject line examples:
- This poster scared 5 out of 6 of our employees
- This financial mistake is hurting 94% of seniors
- This debate is driving opinion: Red? Or Purple?
2. Humor
The humor email subject line formula:
Humor is one of our favorite ways to write email subject lines that work. Can you write a joke and a punchline in less than about 10 words? Or find one on the web you could repurpose?
If so, you might have a fantastic subject line on your hands.
Be careful with humor—what’s funny to one person might not be funny at all to someone else.
That’s especially true if you are emailing a list that includes people from all over the world (as we often do).
However, humor is often ideal when sending an email in one-to-one situations. Sales outreach, for example, is a great situation to lean into humor as a way to get a response.
Who doesn’t like an unexpected laugh when going through their email?
Pro tip: If you can find lists of dad jokes that are appropriate for your recipient or your audience, then customize them as subject lines, those often work extremely well.
Humor email subject line examples:
- What kind of shoes do ninjas wear? Sneakers!
- Steve left his laptop open so we wrote you this email
- I like telling Dad jokes. Sometimes, he laughs!
3: FOMO (Fear of Missing Out)
The FOMO email subject line formula:
FOMO is real.
And you can use the fear of missing out by simply formatting your subject line in a way that takes advantage of this fear.
That means adding an element of scarcity (e.g. “available to the first 100 people”), urgency (e.g. “enrollment closes on Thursday at 5 p.m.!”), or both!
You can also include words or phrases such as:
- Urgent!
- Breaking
- Important
- Alert!
- Limited time!
FOMO email subject line examples:
- [URGENT] Sale ends in 2 hours!
- [ONLY 100 TICKETS LEFT] Reserve yours now before it’s too late!
- [TONIGHT ONLY] Buy 1 get 1 free!
4. Envy
The envy subject line formula:
From entrepreneurs to celebrities, people often look at others who appear to “have it all”—and wish they could live that life too.
To tap into envy as a subject line:
- Reference a celebrity or an authority.
- Add something that they’ve either purchased or invested in.
The key here is to pick a celebrity or authority that the people in your audience already know and look up to.
You can choose a person (e.g. “Elon Musk”) or a group of people in a specific category (e.g. “hedge fund managers”).
Examples of envy email subject lines:
- The pros love this sweatshirt
- 7 celebrities shopping our spring styles (with pictures!)
- Hedge fund managers are quietly picking up this stock
5. Math
The math subject line formula:
You may not see this one in many of the other lists about subject lines, but we have found it works great as a subject line.
Visually, it really stands out in the inbox against all the other text-based emails your recipient might be scanning through.
And there’s just something delightfully simple about a math equation. It’s hard not to open the message to get the rest of the story.
Examples of math email subject lines:
- Your skills + This job opportunity = Success!
- Cold weather + Hard work = Gains!
- Angry customers + These 5 templates = Problems solved!
6. Pain
The pain email subject line formula:
We are wired to avoid painful situations even more than we’re wired to go after success.
For that reason, invoking potential pain is one of the most effective tactics you can use when writing persuasive content—including subject lines.
For this reason, pain or fear-based subject lines are extremely common.
<h4″>Examples of pain-based email subject lines:
- Textbooks too expensive? Here’s an alternative
- Stuck in your career? Try this
- Hate your boss? Do these 3 things
7. Personal Connection
The personal connection email subject line formula:
This last one is specifically for those of you doing one-to-one outreach.
Almost nothing will help your open and response rates more than getting a referral or a recommendation from others—then mentioning that person in an outreach message.
Examples of personal connection email subject lines:
- Josh Anderson said I should reach out to you…
- Sarah Nichols told me you might be interested…
- Shanna Reeves pointed me in your direction…
Email Subject Lines That Work
You’re now equipped with a bank of email subject lines to help you get better open rates and better engagement.
Be sure to follow proper email etiquette when sending your messages.
Make sure you format your emails correctly, and then establish a method to send out your email campaign!
We have two email marketing solutions you can try for free—and both work directly within Gmail.
1. Email Templates
If you’re wanting to send a beautifully designed email, don’t think that you need to create it from scratch (though you can, if you wanted to). Instead, find an email you received that you think looks fantastic, and appropriate it as your own with just a click of a button. We’re not even kidding—it’s that easy—just change out the text and images for your own branding and messaging, and you’re done.
Gmail Email Templates is free to use, and is about to become the most indispensable tool you have in your marketing arsenal. Take a look:
2. MailKing for Email Campaigns
MailKing turns Gmail into a fully-featured email broadcast system. It’s perfect for keeping in touch with customers, prospects, or subscribers.
MailKing is unique because it sends emails from your personal Gmail account. Most email systems simply insert your email address into their system as the “sender.”
Using your personal Gmail means you’ll get better delivery rates, better open rates, and better results overall!
