50+ Cold Email Subject Line Examples to Boost Open Rates

You’ve crafted the perfect cold sales email and you’re ready to captivate your audience.

“KPIs, I’m coming for you!”

But wait, something’s still missing. And this “something” can greatly impact the performance of your cold emails.

“Oh no, I still need to write the subject line,” you sigh.

This guide is dedicated to the unsung heroes of your outreach email success–cold email subject lines. Learn how to craft attractive opening lines that will spark recipients’ curiosity and elevate your open rates. Plus, find cold email subject line examples for different purposes to get inspired.

What Is a Cold Email?

Cold emails are sent to email recipients you haven’t contacted before to introduce yourself or your business. They can serve multiple goals, including lead generation, sales, networking, or event promotion. It’s an affordable email marketing tactic that can lead to new business opportunities and benefit both parties.

While cold email outreach is usually handled by sales and marketing professionals in SaaS and B2B, it’s a common practice in B2C, too. Here’s an example of a cold email we recently received, which was descriptive and to-the point:

Subject line: Content Collaboration between Moosend & [Company Name]

Most marketing and sales reps use cold email marketing software and CRM solutions to manage these emails end-to-end. Email marketing platforms like Moosend are also handy—they offer various segmentation, automation, and personalization tools to build cold email sequences that will make an impression.

Good copywriting skills are essential to convince recipients to open and respond to those emails. With an average open rate at 24% and a response rate at 8%, it takes effort to meet your readers’ expectations and needs. But with the right copywriting and strategic tactics, you can improve your metrics.

Why You Should Create High-Quality Cold Email Subject Lines

Effective cold email subject lines are like keys to treasure troves. Without them, all the goods will simply go to waste. Here are some of the benefits of a compelling cold email subject line:

• Boost open rates: A well-written subject line can make a strong first impression and encourage readers to open emails out of curiosity.
• Stand out in the inbox: Attractive subject lines can grab readers’ attention in crowded inboxes and yield higher open rates.
• Build trust: A clear and authentic subject line helps recipients feel at ease and show trust in the senders’ intentions.
• Increase engagement: Great opening lines set the tone of what recipients can expect from the email content to encourage interested recipients to interact with it.
• Create a sense of urgency: When targeted to pain points or solutions and backed up with numbers or time-sensitive cues, they can instill FOMO and anticipation.

But what materials make resilient keys? From asking quick questions, to offering limited time offers, to addressing prospects’ pain points, you can try different tactics to find what suits your target audience.

50 Best Cold Email Subject Lines for Different Scenarios

Browse through this table to find attention-grabbing subject lines for winning cold emails. Find examples for different scenarios and customize them based on your needs.

To improve or tailor one of these copy suggestions, you can use an AI writer. Type the right prompts and deliver stunning subject lines to your target audience.

Try Moosend’s AI

Most Common Types of Cold Emails

A cold email outreach can serve various purposes, based on the categorization above. Nevertheless, your subject line should perfectly align with the email content to hint to recipients what your email is about and indulge them to open it.

Let’s see some of the most popular cold email types:

Sales and lead generation

Sales reps seek quality leads and take part in converting them into customers. A sales pitch usually aims at closing demos and free trials, but to present it, you need a catchy subject line to impress first. Cold emails are also valuable for marketers trying to move high-quality leads down the funnel through content, such as eBooks or blog posts.

Here’s a cold email template inviting recipients to boost sales significantly:

Relationship building

Cold emails are also popular for networking. You can introduce your brand to businesses you’d like to partner with for mutual benefit. For instance, growth marketers often reach out to successful blogs for link exchange to boost website traffic.

Here’s a collaboration cold outreach email to get a better grasp. The subject line says it all:

Follow-up and engagement

Cold email campaigns don’t always result in great metrics, but this doesn’t mean you should just give up. Your recipients’ inboxes are most likely packed with heavy loads of emails already, but a well-written follow-up email can flip the story. Especially if the copy is spotless, from head to toe.

Growth opportunities

What about professionals who want to reach out to an investor or a business for potential opportunities? While it first sounds like a challenging task, sending cold emails is much better than staying silent. In fact, many people appreciate that courage and give those senders a shot.

Event promotion

Many marketers send cold email invitations to high-quality leads to promote events, such as webinars and workshops and boost registrations and attendance rates.

Here’s another example, addressing a pain point and a benefit to attract readers:

7 Cold Email Subject Line Best Practices

Want to create a cold email subject line from scratch? Here are some easy tactics to craft copy that won’t go unnoticed:

1. Keep it short and urgent

Snappy and short subject lines, between 20 to 40 characters, receive a higher open rate than longer versions. They’re easier to read and optimized for tablets and mobile devices. Adding a splash of color through emojis is also a clever tactic to attract attention.

The word count is not the only factor securing a great subject line. Choose actionable words and phrases that reflect the email content and add a sense of urgency to promotional cold emails. Phrases like “exclusive invitation” or “limited time” can motivate readers to act faster.

2. Craft personalized subject lines

While a good subject line can attract most recipients, personalizing them can yield more email open rates. People respond faster to messaging that resonates with them. One effortless way to do this is by adding the recipient’s name through custom fields.

You can also add a form of social proof, such as the name of the person who introduced you to the recipient, or the source you read about them. Include this information organically inside the subject line and continue with personalized email content to sustain that effect.

3. Highlight the value of your email

Every sales or marketing strategy should meet two important requirements to flourish: bring value to the customer and build anticipation around your brand offer. The same applies to your subject line. Not only should it attract recipients but also instill a fear of missing out early on.

If you read the different subject lines of the previous section more carefully, you’ll see that many include pain points and challenges. Readers recognize something they want to tackle faster, including the benefit of opening this email. Just ensure that their pain points align with what you can offer them.

4. Choose the right timing

A great subject line goes hand in hand with perfect timing to maximize its potential. Salesmate pinpoints a specific timeframe that can lead to winning results: 4-8 AM, followed by 8-12 AM.

These send times secure that your email stays in the first positions in your recipients’ inboxes every morning they log in to receive the attention they deserve. Sending them on Tuesdays and Thursdays is best to secure open rates and responses. Finally, before sending a cold email, consider the time zone of your recipients.

5. Re-engage recipients through follow-ups

No matter how catchy your cold email subject lines are, you’ll often need to master your follow-ups to capture the attention of potential customers. Craft compelling subject line versions of your initial copy for inactive readers to boost open rates and conversions.

From offering more insights, to adding urgency cues, to asking questions about their thoughts on a topic, decide what’s best for your audience and give it to them. To ensure that these subscribers receive a follow-up, use email automation software like Moosend with premade workflows to set them up in advance.

6. Experiment with A/B testing

Sometimes following best practices is not enough to craft converting subject lines. Applying a data-driven tactic leads to safer decisions, highlighting what your target audience is more intrigued by.

A/B testing is a valuable tool for every salesperson or marketer, helping them choose between different writing styles, among other elements. For example, try out a subject line with a more urgent tone and a simple question to find which version attracts more open and conversion rates and send it to most of your recipients.

7. Avoid spam folders—and words

Did you know that adding certain words to your subject lines can signal to spam filters that your content is flaky, putting deliverability at risk? Or worse, make recipients drag your emails to the spam folder themselves?

First, ensure that your sender name and email address are official and contain your business name. Avoid sending from no-reply addresses as you’ll block responses. Finally, remove spam trigger words such as “extra cash” or “no hidden costs” and “very urgent” to purify your content.

Keep Cold Email Subject Lines Warmed Up

Picture your recipients sitting at their desks on a busy day trying to cross out tasks from their checklist. What subject line would capture their attention under these hectic conditions?

Of course, an AI writer will always be there to simplify the process. Just help the virtual assistant visualize the recipient, too, to reach a consensus.