Copywriting guide

Guide to Writing Effective Cold Emails

"How to Write a Cold Email?"

This is one of the most complex parts of outbound – partly because copywriting is a skill that takes time to develop.

Still, we believe the message itself is EXTREMELY important. It often makes or breaks the campaign. Setting up your infrastructure is easy (especially with Maildoso!), and getting good deliverability is totally doable. But writing a strong email that gets a 20% reply rate? That’s a whole different level.

We’ve analysed thousands of cold emails sent by our clients (over 3,000!), added our own outreach templates, and brought in the experience of our team in both marketing and sales. The result? A guide to help you write a near-perfect email (or at least get pretty close).

Keep it short

“Keep it short” is the golden rule for cold emails.

It always works – and it’s also the rule most often broken. There’s no strict character limit like “never go over 300 characters,” and there’s no magic number that guarantees success.

But here’s the idea: the more text you write, the more words your reader has to dig through.

We suggest fitting everything into 5 sentences:

a greeting, personalization or hook;
a quick mention of the problem;
your offer;
a call to action;
a bit of social proof.

Hi there!

We’ve built a unique technology that makes the employee evaluation process faster and more effective.

Our product is powered by advanced tech and the latest tools to help you get the best results.

We value transparency, growth, and mutual respect. Over the past 8 years, we’ve worked on dozens of complex projects and helped companies grow strong, high-performing teams. Our team of professionals...

Hi!

{{username}}, are you struggling with onboarding new employees?

We focus on employee training and know exactly how to make onboarding simpler and more effective.

Want to talk about how you’re handling onboarding now — and how we could make it better?

Focus on what’s in it for the customer

One of the golden rules of good marketing copy is to help your customer, not talk about yourself or your product. No matter how great your product is, people care more about their own challenges—show how you can solve them, and they’ll pay attention.

Another rule for strong copy: use less “we” (“our product,” “our company”) and more “you” (“you’ll get,” “your results”).

Hi there!

{{firstname}}, have you ever tried influencer marketing?

Influencer marketing is one of the fastest-growing marketing channels because of its great ROI and ability to attract loyal customers.

If you're curious, let's jump on a quick call this week.

Hi there!

{{firstname}}, have you ever tried influencer marketing?

I believe working with creators in the {{company niche}} space could help you reach new people and bring in more leads this month.

We can put together a list of 5 creators for you. Would you mind filling out a quick survey?

Avoid spammy phrases

Let’s be honest—you probably get a bunch of cold emails every week too, right? They usually follow the same script, which makes them easy to spot. You can recognize a sales email from the very first sentence.

It’ll probably say things like “I’m reaching out because I saw…” or “We offer a solution that helps…” or “We’ve already helped companies like [name]…”

Sometimes, our brains are better at filtering spam than any algorithm. As soon as people see these kinds of phrases, they instantly think, “Yep, spam.” Try to clean up your copy and run it through tools like https://mailmeteor.com/spam-checker.

Hi there!

Saw your LinkedIn profile — really liked some of your recent posts.

Do you ever struggle with evaluating employee performance? We’ve got a tool that’s helped companies like AAA and BBB cut costs by 30%.

Would you be open to a short call?

Hi there!

Just a week ago, one of our clients let go of 20 employees after realising their actual performance had dropped 3x, even though they were active in meetings and Slack every day.

Our product shows you the real contribution of each team member.

Want me to show you how it works?

Share real results

Your message will be much more convincing if, instead of just promising results, you share what you’ve already done—include real numbers and examples.

Hi there!

{{firstname}}, do you ever run into trouble finding the right candidates for your IT roles?

We can help with hiring. Our recruiters specialise in matching companies with top talent fast, based on your goals and the current market.

If you have any open roles, we’d be happy to take them on.

Hi there!

{{firstname}}, do you ever run into trouble finding the right candidates for your IT roles?

In April 2025, we helped 42 people get hired—from QA testers to CTOs. The average time to hire was 24 days, and every single one accepted the offer and started working.

If you’ve got open roles, we’d love to help.

Talk like you would in Slack

Slack messages are a great example of how to write cold outreach, and here’s why:

You talk to coworkers with respect, but as equals. You don’t apologise for “taking their time,” and you don’t say things like “we’d be grateful even for a no.” Your tone is confident and professional, and cold emails should be the same.
Slack messages get to the point. They’re short and clear. Cold emails should be 3–5 sentences max.
Even in big companies, work chats sound human. When someone reads your message, they should feel like a real person wrote it.

Hi there!

Maria, do you ever have quarters where your sales don’t hit the goal— and your bonus is suddenly at risk?

I’d love to invite you to a quick session to break down what might be causing the drop and share a game plan that fits your goals and sales strategy.

Hi there!

Maria, I noticed sales were down last quarter.

Anything I can do to help? Let’s jump on a short call and figure out what’s going on. I’ll bring one of our analysts.

What time works for you?

Respect your reader

Sometimes people write cold emails like: “Are your sales tanking and your job on the line? Then this is for you…” or “Top 5 reasons you’re a terrible salesperson.”

This kind of messaging assumes something is wrong with the reader—they’re bad at their job, inexperienced, or just clueless. That kind of tone can feel insulting, and it’s best to avoid it.

Instead of focusing on problems, focus on solutions: not “5 reasons your website sucks,” but “5 ways to make your site better.”

Hi there!

Noticed your website loads slowly. It probably means your developer doesn’t know what they’re doing—or maybe you don’t realise how vital load speed is.

Either way, you’re losing customers every day.

I can fix that for you.

Hi there!

I noticed a few performance issues on your site. A quick PageSpeed Insights check showed that you could double your site’s speed with a few small changes.

I’d be happy to help.

That way, you’ll keep more customers and earn more revenue.

Always test different versions

Even if you write a great cold email that follows all the rules, is that enough to make it work? Not really.

We recommend testing different versions and ideas—maybe one focuses on what the client gets, another on what worked for a similar company, and a third on how the product works.

You can run up to 5 different versions at once, check results in 2–3 days, and keep the one that performs best. (Pro tip: create several slight variations of the winning email to reduce the risk of landing in spam.)

Launched Variant A and Variant B

Launched Variant A, Variant B, Variant C, and Variant D ↓↓↓ Variant B performed the best. All other versions were turned off. ↓↓↓ Launched Variant B#2, Variant B#3, Variant B#4