Your first cold campaign went out Monday. By Wednesday, your emails to clients were landing in spam.
The fix is a proper cold email outreach system: a verified list, two side domains, five warmed inboxes at 30 emails a day, and a three-email sequence that stops on reply. For 1,000 new prospects a month, it costs about $104.
We priced every piece and did the inbox maths. And the part that sinks most setups isn’t the sending tool.
What a working cold email setup costs per month
A setup for 1,000 new prospects a month runs about $104, or roughly 10 cents a prospect. Here’s where the money goes, on annual billing where it’s offered.
| Part | What we’d buy | Monthly cost |
|---|---|---|
| Sending domains | 2 lookalike .com domains (we budget $15 a year each) | About $2.50 |
| Inboxes | 5 Google Workspace Business Starter users at $7 | $35 |
| Leads and verification | Hunter Starter, 2,000 credits | $34 |
| Sequencer | Smartlead Base (6,000 sends, 2,000 contacts) | $32 |
| Total | About $104 |
Notice what’s cheap. Domains and inboxes cost less than a team lunch, yet they decide whether anyone sees your email.
A CRM can wait until replies start piling up. More on that below.
How many inboxes do you need?
Divide your peak daily sends by 30. That’s your inbox count.
Here’s the maths for our 1,000-prospect month. Spread over 21 working days, that’s about 48 new people a day. Each one gets up to three emails, so once the sequence is running you’re sending around 150 emails a day.
At 30 cold emails per inbox, that’s five inboxes. Put three on one domain and two on the other.
Wait. Doesn’t Google let each user send 2,000 emails a day?
It does. That limit is for normal mail, though, and cold email gets judged on complaints, not volume. Thirty a day is our ceiling, not Google’s. A young inbox that suddenly sends 200 cold emails looks exactly like a spammer.
Why your main domain should never send cold email
Cold email burns domain reputation, so you run it on domains you can afford to lose.
Picture yourcompany.com getting flagged. Now your invoices, password resets and client replies start landing in spam too. A side domain like tryyourcompany.com or yourcompanyhq.com takes that hit instead.
Point each side domain at your main website with a redirect, so curious prospects still find you. Then set up SPF, DKIM and DMARC on every one of them. Our SPF, DKIM and DMARC setup guide has the exact records for Google Workspace and Microsoft 365.
Common mistake: buying ten domains and 30 inboxes on day one. You’ll pay for months of warm-up on capacity you don’t need yet. Start at five inboxes and add two at a time.
Step 1: build a list you’d bet a domain on
Your list decides your bounce rate, and your bounce rate decides whether Gmail trusts you. Build it narrow, then verify every address.
Heads-up: the Hunter, Apify and n8n links on this page are affiliate links. Sign up through one and we may get paid, at no cost to you.
Pick one kind of buyer and one offer. Fifty marketing agencies with 10 to 50 staff beat 1,000 random “business owners”. You can write one email that fits all fifty.
Where the emails come from depends on who you’re selling to:
- B2B companies: Hunter‘s Domain Search finds the public addresses at a company domain. One found email costs 1 credit and one verification costs half a credit. Our Hunter.io review covers the accuracy trade-offs.
- Local businesses: scrape Google Maps listings with an Apify Actor, then pull emails from their websites. The Apify Actors walkthrough shows the no-code route.
- Niche lists: directories and member lists, with one of the email scraping tools we’ve compared.
Then verify everything, including emails you bought. Run 1,000 finds and 1,000 verifications through Hunter and you’ve used 1,500 of Starter’s 2,000 monthly credits.
Skip verification and say one address in ten is dead. That’s 100 hard bounces in your first week, from inboxes that are three weeks old. Gmail notices.
Step 2: set up the domains and inboxes
Buy the domains, create the inboxes, authenticate, then wait. Here’s the order we’d follow.
Set up sending domains and inboxes
About an hour of work, then two to three weeks of waiting
-
Step 1 of 5
Register two lookalike domains
Stick to .com and keep the brand name in it. Avoid hyphens and odd endings, which look like throwaway domains to spam filters and to people.
-
Step 2 of 5
Redirect each one to your main site
Use a 301 redirect so anyone who types the domain lands on your real website.
-
Step 3 of 5
Add real inboxes
Create named users like priya@ and priya.k@, with a real photo and signature. Shared aliases such as sales@ get fewer replies and look automated.
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Step 4 of 5
Authenticate every domain
Add SPF, DKIM and DMARC before any email goes out, and check all three pass on a test message.
-
Step 5 of 5
Connect the inboxes to your sequencer
Most tools connect Google Workspace with OAuth. Turn on warm-up the same day.
Google’s trial accounts are capped at 500 emails a day and don’t get raised during the trial. That’s plenty for warm-up, so the trial isn’t a reason to wait.
Step 3: warm up before your first cold email
Warm-up gives a new inbox a sending history before it emails strangers. Give it at least two weeks.
Your sequencer’s warm-up feature trades emails with other inboxes in its network, opens them, replies and pulls them out of spam. Gmail sees a new sender that people seem to want to hear from.
Our rule: in week three, start at 10 cold sends a day per inbox. Add five a day each week until you reach 30, and leave warm-up running the whole time.
Our take: warm-up buys you a starting reputation. It can’t fix a bad list or a pushy email. If real prospects mark you as spam, no amount of fake replies will save the domain.
So the inboxes are ready. What do you actually send them?
Step 4: write a three-email sequence that stops on reply
Three short, plain-text emails over about ten days is enough. Every step after that adds more complaints than replies.
| Send on | Job | Length | |
|---|---|---|---|
| 1 | Day 1 | One specific problem you noticed and one small ask | 50 to 90 words |
| 2 | Day 4 | A reply in the same thread with one new detail, like a result or an example | 30 to 60 words |
| 3 | Day 9 | A polite close: is this worth a chat, or should you stop? | Under 40 words |
Four rules matter more than any template:
- No links or images in email one. Plain text from a person reads like a person.
- Ask for a reply, not a meeting. “Worth a look?” is easier to answer than a calendar link.
- Stop on any reply, including “not interested”. Every sequencer can do this, so check it’s switched on.
- Measure replies, not opens. Apple Mail preloads tracking pixels, so open rates overstate how many people read you.
Send in the prospect’s working hours. A 7 a.m. email to a Mumbai founder sits under 40 others by lunch.
Which sending tool should run the sequence?
For most small teams, a cheap sequencer with plenty of inbox slots is the right call. The tool matters far less than your list and domains.
| Tool | Entry price | What decides it |
|---|---|---|
| Smartlead Base | $39 a month ($32 yearly) | 6,000 sends and 2,000 contacts. Fits our 1,000-prospect month with room to spare |
| Instantly Growth | $47 a month | Unlimited inboxes and warm-up, but uploads stop at 1,000 contacts. Our setup sits right on that line |
| Hunter Starter | $34 a month yearly | Leads, verification and sequences in one bill. Only 3 inbox slots, extras from $10 a month each |
| Reply.io | From $59 per user a month | Warm-up included, plus LinkedIn and calls as paid add-ons. Worth it once a team works the replies |
Here’s the trade-off with Hunter. If you already pay for Starter to find emails, running sequences there saves a second tool. But five inboxes need two extra slots at $10 each, so a separate sequencer is cheaper at our size.
Reply.io makes sense when calls and LinkedIn steps join the email. Our Reply.io review walks through those multichannel sequences.
Where do replies go once people answer?
Every positive reply should land in one place where someone follows up within a day. A spreadsheet works for the first 20.
After that, move replies into a CRM. Close starts at $9 per user a month on yearly billing. Our Close CRM review explains why it suits small outbound teams.
Most sequencers fire a webhook when a lead replies. Catch it in n8n and you can create the CRM contact, tag the campaign and ping Slack in one workflow. If webhooks are new to you, our plain-English webhooks explainer starts from zero.
The numbers that tell you to stop sending
Watch three numbers every week. When one crosses its line, pause that inbox and fix the cause before sending more.
| Signal | Healthy | Pause and fix when |
|---|---|---|
| Hard bounces | Under 2% | Over 3%: re-verify the list |
| Gmail spam rate (Postmaster Tools) | Under 0.1% | Near 0.3%: Google’s own red line |
| Reply rate | Steady week to week | Drops by half: check inbox placement before rewriting copy |
Google’s sender rules ask everyone to stay under 0.1% and never reach 0.3%. Put that in emails. If all 3,000 of your monthly sends went to Gmail, 0.3% is nine spam clicks. The 0.1% target is three.
That’s why the list matters more than the copy. Nine annoyed strangers is a very small margin.
The bounce and reply lines are our own working thresholds. The spam figures are Google’s.
Warning: the US CAN-SPAM Act has no exception for B2B email. Every cold email needs your real postal address and a clear way to opt out. You must honour opt-outs within 10 business days. Penalties reach $53,088 per email.
Emailing people in the EU or UK brings GDPR in too. That’s a question for your lawyer, not a setting in your sequencer.
How we put this together
This guide is research and maths, not a campaign we ran for this post. We haven’t sent a test sequence through these tools, so you won’t find reply rates here. Any number we gave you would be made up.
Every price was checked on the vendor’s own pricing page on 22 October 2026. Sending limits and spam thresholds come from Google’s Workspace help pages, and the legal rules from the FTC’s CAN-SPAM compliance guide.
Frequently asked questions
Can I use Microsoft 365 inboxes instead of Google Workspace?
Yes. The rules don’t change: separate domains, about 30 cold emails a day per inbox, and SPF, DKIM and DMARC on every domain before you send. Some teams split inboxes across both providers so one reputation dip doesn’t stop everything.
Is cold email legal in India?
India has no dedicated anti-spam law for email like CAN-SPAM. The Digital Personal Data Protection Act still covers how you collect and use personal data. Stick to work addresses, say who you are and honour every opt-out. US and EU prospects bring their own laws with them.
Should I buy pre-warmed inboxes?
They save two weeks, not much else. Pre-warmed inboxes still have a short history and still burn on a bad list. Reply.io sells them from $15 per mailbox a month, about double a Workspace seat. That only pays off when a launch date can’t wait.
How long before a cold email setup gets replies?
Plan for about a month. Two to three weeks of warm-up, then a week of ramping sends, then your first sequence needs ten days to finish. Judge the campaign on replies after the full sequence, not on day-one results.
What happens if one of my sending domains gets blacklisted?
Pause every inbox on that domain, keep warm-up running, and stop cold sends for two to three weeks. Check the list and copy that caused it. If placement doesn’t recover, retire the domain and bring in a new one, which is why side domains exist.
Do I need a dedicated IP address for cold email?
No. Google Workspace and Microsoft 365 send from shared, well-kept IP ranges, which is part of why they work for small senders. A dedicated IP only helps at steady volume in the tens of thousands a day. A new one starts with no reputation at all.
Can I add more prospects without more inboxes?
Only by adding fewer steps or slower ramps, and neither helps much. The honest way is two more inboxes for every extra 60 sends a day. Add them on a new domain, warm them for two weeks, then shift part of the volume across.
The bottom line
A cold email outreach system works when the boring parts are right. That means a verified list, side domains, warmed inboxes at 30 a day and a short three-email sequence.
Starting out solo? Run Hunter for leads and Smartlead for sending, at about $104 a month. Hunter alone is fine if three inboxes cover you. Bring in Reply.io when a team starts adding calls and LinkedIn.
Whatever you pick, keep cold email off your main domain. Your next step: buy two lookalike domains today, so they’re warmed and ready in three weeks.
