Cold email is a message to someone who never asked to hear from you. You picked them because they fit your market. Email marketing goes to people who gave you their address and agreed to get your emails: subscribers, sign-ups, customers.
The two can use the same words and land in the same inbox. What separates them is permission. It decides which list you may load, which platform will send it, which legal route you rely on and what a good result looks like.
The legal short version: US federal law, the CAN-SPAM Act, covers both with almost the same rules, and business-to-business email gets no exemption.
In the EU and the UK, marketing email to individuals normally needs consent. For business contacts, each country's email marketing rules apply.
On top of those rules, the named contact's personal data needs a lawful basis. Legitimate interests can be one, but only after a test that weighs your interest against that person's rights.
Every rule quoted on this page was read at its source in September 2026.
Cold email is what my team sends every week, so treat me as someone with a side. Smirnov Consulting Group is a Prague-based B2B outbound lead generation agency that runs cold email and LinkedIn campaigns for founder-led B2B companies and books qualified sales calls.
In a post on how I build follow-up sequences I wrote the line that sums up the practical gap: "Cold email gets a shorter sequence, usually four steps, because you have less permission and more suspicion to work against."
What counts as cold email, and what counts as email marketing?
Cold email. The person has no relationship with you. You found them through research: a job title, a company size, a country. In B2B it mostly starts sales conversations with decision-makers, and some companies use it for partnerships or hiring too. This article is about the sales kind.
Email marketing. The person opted in or bought from you. A newsletter, a product update, an offer to past customers, a nurture series after someone downloads a guide. Its job is to keep a relationship going with people who already know you.
Two more labels muddy the picture.
Warm email. In my campaigns this means an email that follows a first touch somewhere else, usually a LinkedIn connection, so your name is not new to them. A connection request is not an email sign-up, though. Run warm email under the cold email rules.
Transactional email. Receipts, password resets, updates on a deal both sides already agreed.
The FTC's CAN-SPAM compliance guide sorts messages by their "primary purpose". Content that promotes a product or service is commercial. Content that supports a deal already agreed, or content that "updates a customer about an ongoing transaction", is transactional or relationship content.
Cold email and email marketing side by side
| Cold email | Email marketing | |
|---|---|---|
| Who gets it | People who fit your market and never contacted you | People who opted in or bought from you |
| Where the list comes from | Built for the campaign, then verified address by address | Collected by you: forms, purchases, event sign-ups |
| US rules | CAN-SPAM: no consent step, opt-out honored, no B2B exception | CAN-SPAM: the same rules, except the ad label for people who gave prior consent |
| EU and UK rules | Consent for individuals; for business contacts, national rules plus the GDPR (the UK GDPR in the UK) | Consent, or the soft opt-in for your own customers |
| Sending platform | A cold sending tool spread over several mailboxes | A newsletter platform such as Mailchimp |
| Sending domain | Separate domains, never the one your company runs on | Your brand domain, authenticated |
| Sequence length | About four steps, then stop | As long as the reader stays subscribed |
| What you count | Replies, conversations, booked calls | Clicks, unsubscribes, sales from the list |
| What happens to the list | It runs down as people finish the sequence | It grows and gets emailed again |
The last row is easy to miss. A marketing list compounds. A cold list gets spent, because you cannot keep writing to the same strangers every month.
Is cold email legal, and does email marketing need consent?
European and UK law turn on whether the reader agreed, which is what separates the two channels, and on whether the reader is a person or a company. US federal law treats both channels almost the same way; the ad label rule, covered below, is where they differ.
United States: one federal law for both
The FTC guide lists eight requirements for commercial email:
- Header details (From, To, Reply-To and routing) must be accurate and identify who sent it.
- The subject line must not mislead.
- The message must say clearly that it is an advertisement. The Act itself makes an exception here for people who consented, explained below the list.
- It must include your valid physical postal address.
- It must tell people how to opt out of future email.
- Subscribers and members keep that right to opt out of your marketing too.
- Opt-outs are honored within 10 business days, free of charge, asking for nothing beyond an email address and no step beyond a reply email or a visit to one web page.
- If another company sends for you, the legal duty stays with you. The FTC says you cannot contract it away.
None of the eight asks for permission before the first send. By these rules, a cold email that meets all eight may go out without consent. Once the person opts out, the emails stop within the 10 business days in item 7. Your newsletter lives under the same guide.
Permission does change the ad label rule. The statute says the advertisement label "does not apply to the transmission of a commercial electronic mail message if the recipient has given prior affirmative consent to receipt of the message" (15 U.S.C. 7704(a)(5)(B)).
So a newsletter sent to people who explicitly opted in can skip that label. A cold email cannot, because nobody on a cold list gave that consent.
The guide says "the law makes no exception for business-to-business email." Each separate email in violation can cost up to $53,088, the FTC figure as of September 2026. A campaign of 1,000 non-compliant emails is 1,000 separate violations.
European Union: consent for people, national rules for companies
The ePrivacy Directive, Article 13, allows marketing email to individuals only with their prior consent.
The one exception covers your own customers. If you got their address in a sale, you may market your own similar products, as long as they could object for free when you collected it and in every message since.
Every marketing email must also show who is sending and give a valid address for opting out.
For companies as recipients, the consent rule does not apply, and each member state decides how to protect them. That is why the answer to "can I cold email a business in Europe" can change from one country to the next.
The GDPR still covers the named person behind a company address. Recital 47 says direct marketing may count as a legitimate interest, unless that person's interests and rights override it, judged partly by what they could reasonably expect.
Article 21 lets that person object to direct marketing at any time. Once they do, their data may no longer be used for it.
United Kingdom: companies yes, sole traders no
The ICO's business-to-business marketing guidance says you can email companies (the ICO calls them corporate subscribers) without consent. The email has to name you honestly and offer a working address for opting out.
Sole traders, and some partnerships, are treated like private individuals and need consent unless the soft opt-in applies.
The name and work email of a person at a company are still personal data. For that data, the ICO says legitimate interests can apply when the UK email rules (PECR) do not require consent, with a three-part test: name the interest, show the email is necessary for it, and weigh it against the person's rights.
The ICO adds that there is no absolute rule here. The test decides whether you can use that basis for your campaign.
One caution. The ICO page carries a notice that this guidance is being reviewed, and could change, because the Data (Use and Access) Act amended the rules.
This is not legal advice. Check your own country with someone qualified.
Why Mailchimp will not carry your cold email
Mailchimp is built for lists you collected yourself, and it puts that rule in writing.
Mailchimp's audience requirements state: "Third-party lists of email addresses or phone numbers are prohibited under our Terms of Use. This includes purchased or rented lists, and lists scraped from third-party sources, including public websites."
The same page says contacts should be collected by you, and warns that poor list maintenance can lead Mailchimp to shut the account down.
Mailchimp's Acceptable Use Policy, updated 26 September 2025, also expects you to be able to point to an opt-in form or other proof of consent for every marketing email you send.
A cold list fails that test by definition. So cold email runs on a different stack, and the domain matters as much as the tool.
My rule, spelled out in the post on sending setup, is that cold campaigns never go out from the domain your company runs on. The reputation risk of cold sending has no ceiling. Once the main domain is flagged, invoices, support replies and contracts begin to land in spam beside the outreach.
Google publishes where the line is. Its sender guidelines ask all senders to stay under a 0.3% spam rate, as measured in Postmaster Tools, and to aim below 0.1%.
Past 5,000 daily messages to Gmail addresses, a sender also needs DMARC, and its marketing and subscribed mail must offer one-click unsubscribe.
What the cold side needs instead, in short:
- A list built for the campaign from Sales Navigator or a B2B database, filtered to the right titles
- Separate domains close to your brand name, each authenticated with SPF, DKIM and DMARC
- Several mailboxes that send modest daily volumes, warmed up before they reach a prospect
- A sending tool built to spread a campaign across those mailboxes
- Every address checked before use; my team runs NeverBounce, sometimes DeBounce, and holds bounces below 0.5%
Lists are where most cold email problems start. Your list decides more than your copy, and a list full of dead addresses is how a sending domain gets flagged.
Which one are you running? Five questions
Answer these for each address on the list you are about to send, and split the list if the answers differ.
| Question | A yes means | A no means |
|---|---|---|
| 1. Did every person on the list give you their address themselves, on a form, at an event or as a customer? | Keep going | The rest are cold, including anything from a data vendor, a scraper or a freelancer |
| 2. Did each of them agree to marketing email, or buy from you, with an easy opt-out offered then and in every message since? | Email marketing (the soft opt-in covers only your own similar products) | Cold |
| 3. Does any cold address belong to a private individual in the EU or the UK, or to a UK sole trader? | Take them off: marketing email to them needs consent | Keep going |
| 4. Have the cold ones seen your name before, for example by accepting a LinkedIn request? | Warm, still under cold rules | Cold |
| 5. Is the goal a first conversation with someone new? | A short cold or warm sequence, on the cold stack | Only for addresses that passed questions 1 and 2: a newsletter or nurture email on your marketing platform. Cold addresses get no newsletter |
Anything that lands on cold gets the cold treatment, whatever the campaign is called inside your company: separate domains, a verified list, a short sequence, and a legal route that works in that person's country.
You can run both. Cold email opens conversations with people who have never heard of you, and the newsletter stays in touch with people who asked to hear more. Keep the two on separate lists, domains and tools, and move a person across only when they say yes.
When each one is the wrong choice
Each channel fails in a way that follows from what defines it. Email marketing needs permission you may not have yet. Cold email uses up its list, and it needs an offer that already sells.
Email marketing
You have no list yet. Buying one does not give you a marketing list. It gives you a cold list on the wrong platform.
You need buyers who have never heard of you. A newsletter reaches only people who already gave you their address, so on its own it cannot open a first conversation with a new account.
Cold email
Your market is small enough to run out. Say you sell to 1,500 companies with 2 relevant buyers in each. That is 3,000 people.
Across my campaigns, a booked call has needed 150 to 250 people contacted, a planning range I walk through in my notes on choosing a market. So the whole market is worth roughly 12 to 20 booked calls, once.
A newsletter changes that math. If a few hundred of those same buyers subscribe, you can write to them every month for years. In a small market, plan around that difference before you pick the channel.
Nobody has bought the offer yet. Outbound is for companies with an offer that already sells and clients who got results. It multiplies what works. It will not build the business from zero, and if a first small batch of the right people produces no interest, a bigger batch will not either.
Mistakes that come from mixing them up
Calling a bought list "our marketing list". The soft opt-in covers people whose address you got in a sale (in the UK, also during talks about one), and only for your own similar products. Lists bought from freelancers also tend to give themselves away with high bounces and low open rates, and bought data sits behind several regulator fines.
Uploading prospects into the newsletter tool. The complaints and bounces then land on the account your real subscribers depend on.
Adding cold replies to the newsletter. A reply starts a conversation. Ask before you add anyone, because marketing email to individuals in the EU and the UK needs consent unless the soft opt-in applies.
Writing a cold sequence like a newsletter. Designed templates, banners, a long update about you. A cold email works as a short, human note from one person. It gets about four steps, each with a reason to exist, then it stops.
Judging cold email by newsletter numbers. Count replies, conversations and booked calls. A cold campaign with a modest open rate and ten booked calls is doing its job.
Questions founders ask about the two
Can I send cold email through Mailchimp?
No. Mailchimp prohibits purchased, rented and scraped lists, and expects your contacts to be collected by you. Cold email needs its own sending setup on separate domains.
Do I need consent to cold email a business?
Under US federal law, no: CAN-SPAM works on opt-out and makes no exception for B2B email. In the UK, companies can be emailed without consent, but sole traders need it unless the soft opt-in applies. In the EU, the rules for companies are set country by country, and the GDPR still covers the named person you write to.
Can I add people who replied to my cold email to my newsletter?
Ask them first, and add only the ones who say yes. A reply is interest in a conversation, and the consent rules for marketing email to individuals still apply in the EU and the UK.
Is warm email the same as cold email?
For the rules, yes. Warm email follows a first touch such as a LinkedIn connection, so the reader already knows your name, but they never signed up for your email. It is still unsolicited.