15 Most Common Questions About Cold Email (And Answers to Each)

Introduction: Everything You Wanted to Ask but Didn’t Know Who to Ask

Cold email is one of the most effective ways to acquire B2B clients. But it is also one of the least understood. There are many myths, scare tactics, and half-truths surrounding it that deter people from even starting.

This article answers the 15 most common questions we receive — from the absolute basics to advanced topics. No unnecessary jargon and no evasive answers.

1. What is cold email?

Cold email is a personalized message sent to a company or person with whom you have not previously communicated. It is not spam — it is a relevant, targeted message that offers a solution to a specific problem.

Example: You find an online store that does not have active Google Ads campaigns. You write a short email to the owner mentioning this issue and offering a solution. That is cold email.

The difference from spam: spam is a mass, irrelevant message sent to thousands of people without any context. Cold email is a personalized message sent to a specific person with a relevant offer.

2. Is cold email legal?

In the B2B context, yes — in most European countries. GDPR allows contacting businesses based on legitimate interest, provided the message is relevant, the sender identifies themselves, and the recipient has the option to opt-out.

Cold email is not prohibited. It is regulated. And if you follow the rules — personalization, identification, opt-out option — you are operating within the law. More detailed information can be found in our two articles on GDPR and cold email.

3. What is the average reply rate for cold email?

The average reply rate is 3–5%. This means that out of 1,000 sent emails, 30–50 people will reply. Top performers achieve 10–15%, but this requires excellent personalization, correct data, and tested emails.

If your reply rate is below 1%, the problem lies either in the quality of the data (bad contacts), in the email (generic, too long, irrelevant), or in the target group (you are targeting the wrong companies).

4. How many emails can I send per day?

It depends on your infrastructure. From one email account, it is safe to send 20–30 emails per day. If you have 5 accounts, that is 100–150 emails per day. If you have 10 accounts, 200–300 per day.

The key is not to exceed the limits of individual accounts — otherwise, you risk having your domain blocked and reduced deliverability. Distributing the volume across multiple accounts with automatic rotation is standard practice.

5. How much does cold email cost?

If you use a platform like DataSend.ai with built-in databases, campaigns, and CRM, costs start from $89/month. Add domain costs ($10–15 per domain per year) and email accounts ($3–7 per account per month). For a typical operation with 5 accounts, it totals around $120–150 per month.

Compare this to Google Ads (minimum €750–2,500/month) or cold calling (€2,000–5,000/month) and you see why cold email is the cheapest channel for B2B acquisition.

6. How long should a cold email be?

50–80 words is optimal. A maximum of 120 words. Shorter emails have a higher reply rate because they are quick to read and do not require a significant decision from the recipient.

If you have to scroll to read the entire email — it is too long. Cold email is not an offer, it is not a newsletter, and it is not a presentation. It is a short message aimed at starting a conversation.

7. What should I write in the subject line?

Short subject lines (2–5 words) that look like regular business communication. Avoid marketing phrases, exclamation marks, and capital letters.

Good examples: "Question about [company]" / "[Company] + Google Ads" / "Quick Proposal" / "[Name], quick question"

Bad examples: "BOOST YOUR REVENUE BY 300%!!!" / "Exclusive Offer for Your Company" / "Don’t Miss This Opportunity"

The subject line determines whether the email will be opened or not. If the subject looks like an advertisement, it won’t be opened.

8. Should I send follow-ups?

Yes — always. 42% of all replies to cold emails come from follow-ups, not from the first email. If you only send one email and wait, you are missing out on almost half of the results.

The optimal sequence: 3–5 emails spaced 3–7 days apart. Each follow-up should bring something new — not just "I wanted to make sure you received my previous email." After 3–4 follow-ups, stop. If they haven’t replied after 4 emails, they probably aren’t interested.

In DataSend.ai, you can set up the entire follow-up sequence in advance, and the system sends reminders automatically according to the set schedule.

9. Where should I get contacts from?

From verified sources — databases that draw from business registers, public sources, and company websites. Not from unknown purchased lists, not from scraped LinkedIn, and not from data leaks.

DataSend.ai includes a database of over 9M companies in 7 European countries with verified contacts. Filters by industry, region, revenue, company size, and web score allow you to find exactly the companies that match your target audience.

10. What is warmup and why do I need it?

Warmup is the process of building the reputation of an email account before you start sending cold emails. A new email account without history lacks credibility — and emails from it often end up in spam.

During warmup, the system automatically sends and receives emails from your account — simulating regular email communication. This builds reputation with providers like Gmail and Outlook. Warmup typically takes 14–21 days before the first campaign.

DataSend.ai has built-in warmup with AI-generated conversations — you don’t need to deal with any external tool.

11. What if no one replies?

If you have a reply rate of 0% after 200+ emails, something is wrong. The three most common causes:

Bad data. If 30% of emails bounce, your domain suffers and the rest of the emails end up in spam. Solution: use verified contacts with a bounce rate below 5%.

Bad email. Generic, too long, or irrelevant. Solution: shorten to 50–80 words, personalize, change the subject.

Bad target group. You are targeting companies that do not need your service. Solution: reassess your filters and choose a more relevant segment.

12. How many companies do I need to contact to get one client?

With an average reply rate of 3–5% and a conversion of 5–10% from replies to clients, you need to contact about 500–1,000 companies for one paying client. With better results (higher reply rate, better conversion), it can be 200–400.

That sounds like a lot, but with a platform that has a database and automated campaigns, it’s a matter of days, not months. In DataSend.ai, you can find 500 companies in 10 minutes and launch a campaign immediately.

13. Should I send cold emails in English or in the local language?

In the local language — always. An email in English to a German company signals "I am a global company and do not adapt." An email in proper German signals "I understand your market and take you seriously."

In Europe, language is a trust filter. But be careful — bad grammar is worse than English. If you do not master the language at a professional level, use AI tools to check grammar. In DataSend.ai, AI Grammar Variables automatically generate correct grammatical forms in 6 languages — "in Bratislava," "im Bauwesen," "w Warszawie" — without your intervention.

14. What is Unibox?

Unibox is a centralized inbox where you can see replies from all your email accounts in one place. Instead of switching between 5 inboxes, you have one space where all replies are sorted and categorized.

In DataSend.ai, Unibox automatically analyzes each reply using AI — determining the level of interest, sentiment, urgency, and recommended action (call, send an offer, follow up later, disqualify). You don’t have to read every email and decide — AI does it for you, and you just filter and respond.

15. How long until I see the first results?

14–21 days of warmup + 1–2 weeks for the first replies. Realistically — you will see the first replies within 3–5 weeks from the start. The first client within 4–8 weeks.

This is not an instant channel like paid advertising. But unlike advertising — where you pay for every click — cold email costs you a fraction and the results are sustainable. Once you have a tested email and a working sequence, the system runs predictably month after month.

Conclusion: Cold email is not complicated. It is just unknown.

Most questions about cold email stem from ignorance, not from its complexity. Once you understand the basics — what it is, how it works, what to write, and to whom — it is one of the easiest and cheapest ways to acquire B2B clients.

You don’t have to become an expert before you start. Just find 50 companies, write to them, and see what happens. You will learn the rest through practice.

Want to try cold email in practice? DataSend.ai — a database of companies, email campaigns with AI personalization, automatic follow-ups, Unibox, and pipeline. Everything in one place, free to start.

Try it for free →