How to start cold emailing: your first campaign in 30 days

This is the plan I give people starting cold email from nothing. I've run cold email for my own companies and for clients for over six years, around 12 million emails in all, and the setup below is the one I still use. It takes about a month, and most of that month is waiting for new mailboxes to warm up, so the work fits around a normal week.

The short version: decide exactly who you're emailing, set up separate sending domains with three mailboxes each, warm them for two weeks while you build and verify a list, write one email and three follow-ups, then launch slowly and judge by replies.

Before you start: what it costs and what to expect

You need a few sending domains, a handful of mailboxes, a lead list, verification and a tool to send sequences and handle replies. On mailzy that's mailboxes at $4 each a month, lead lists from $25 per 10,000, and an Outreach plan from $27 a month, with a free trial.

Set your expectations honestly. On my good campaigns, the reply rate sits around 1 to 3%. That sounds small until you do the maths: 2,500 people a month at 2% is 50 replies, and if a fifth of those are interested, that's ten real conversations a month from a channel you control.

Week 1: decide who, then set up

Write your two sentences

Before buying anything, write down who you're emailing: the kind of company, its size, where it is, and the job title of the person who says yes. Then write the one problem you solve for them. If you can't do both in a sentence each, the campaign isn't ready yet. This is your ideal customer profile in its shortest form, and every later step depends on it.

Work out how many mailboxes you need

Work backwards from how many people you want to reach. My rule: about 30 cold emails per mailbox per day once it's warmed up, and three mailboxes per domain. Each person gets four emails (one plus three follow-ups), so reaching 2,500 people a month is about 10,000 emails, or roughly 500 a day over 20 working days. That's around 17 mailboxes on 6 domains.

For a first campaign, start smaller: 6 to 9 mailboxes on 2 or 3 domains reaches 1,000 to 2,500 people a month. The mailbox calculator gives you the exact number for your goal.

Buy separate sending domains

Never send cold email from your main company domain. Buy two or three secondary domains close to your brand: getyourbrand.com, yourbrandhq.com. Stick to .com where you can, avoid hyphens and numbers, and point each one's website at your main site so anyone who checks finds you.

Set up mailboxes and DNS

Use real mailboxes from a major provider: Google Workspace is what I use. Give each mailbox a real person's name, a photo and a short signature. Then add four records to every domain:

• SPF, listing your mail provider's servers.
• DKIM, with signing switched on in the provider.
• DMARC, starting at p=none with a report address.
• An MX record, so replies arrive.

Check every domain with the domain health checker. When they all pass, switch on warm-up for every mailbox. From here the clock runs: I warm new mailboxes for about 14 days before their first campaign.

Week 2: build the list

While the mailboxes warm up, build your list from your two sentences. Pull more people than you need, because some drop out at each step.

1. Export from your lead source (Apollo or LinkedIn Sales Navigator, filtered by your profile), or order a list built from your search.
2. Clean it: duplicates out, names and company names fixed so they read naturally, one column per field. The email list cleaner does the tidy-up in your browser.
3. Remove customers, competitors and anyone who opted out before. Keep these on a suppression list for good.
4. Verify every address. Keep Valid, set catch-all aside, remove the rest. This is the step people skip and regret: a bad list is the most common reason I've seen campaigns fail.

Add one or two columns that let you personalise: what each company does, or something recent about them, such as a job post or a launch.

Week 3: write the sequence

The first email

Write it under 80 words: a first line about them, the problem, what you do with one real result, and one easy question. No links, no images, no attachments. Read it out loud; if it sounds like an advert, rewrite it. The guide to writing a cold email goes through each part, and the cold email grader checks length and readability.

Three follow-ups

I use one main email and three follow-ups: the first follow-up three days after the main email, the second five days after that, and the last seven days after that. The gaps grow so the emails feel patient. Each one is shorter than the last and adds something new: an example, a different angle, then a polite close. All of them reply in the same thread.

Two versions to test

Write a second version of the first email that changes one thing: the opening, the proof or the question. Change ideas, not just words, so the test tells you something.

The schedule

Send on working days, in a few morning hours in your prospects' time zone, stop on any reply, and include a way to opt out. The send window planner helps when your list spans time zones.

Week 4: launch small, then grow

Your mailboxes now have about two weeks of warm-up. Launch to a small slice: about a fifth of each mailbox's daily number on day one, raised over the following week. Keep warm-up running underneath; it doesn't stop when campaigns start.

Watch three numbers from the first day:

• Bounces under 2%. Above that, pause and fix the list before anything else.
• Replies of any kind. Even "not interested" proves the email reached a person.
• Positive replies, the number that pays for everything else.

After day 30: judge, then change one thing

Give the campaign two to three weeks before judging the copy, because a large share of replies come from the follow-ups. Then change one thing at a time, in this order:

1. The list. Wrong people is the commonest cause of silence.
2. The offer. If the right people don't want it, better words won't help.
3. The first line and the question.

Add mailboxes a month before you need the extra volume, so they're warmed up in time.

The mistakes I see most

• Too much, too soon: high volume from domains bought last week, with no warm-up.
• Missing or broken SPF, DKIM or DMARC.
• Unverified lists, which burn new domains through bounces.
• Emails that look like marketing: heavy links, images and tracking.
• Judging after three days, before the follow-ups have gone out.

Questions people ask

Can I send cold email from my main domain?

You can, but I don't. If a campaign goes wrong, your invoices and customer replies start landing in spam too. Separate sending domains cost little and remove that risk.

How long until I get replies?

The first replies usually arrive in the first week of sending. Judge a campaign after the full sequence has run, two to three weeks after launch.

Is cold email legal?

In the US, yes, under the CAN-SPAM Act, with honest headers, your business address and an easy opt-out. The UK, EU and Canada have stricter rules; see PECR, legitimate interest and CASL.

mailzy covers the whole plan in one place: mailboxes we set up and warm, lead lists and verification, campaigns with schedules and A/B versions, and every reply in one inbox. See Outreach.