How to Buy Domains for Cold Email: Registrars, TLDs and Setup

Last updated July 2026. Registrar prices checked on each registrar's own page.

Buying domains is the cheapest part of a cold email program and the part people get wrong most often. A bad name costs nothing on the invoice and everything in reply rate. For background on how sending domains fit together, start with our guide to choosing and structuring cold email domains.

Why your primary company domain is off limits

Your main domain carries invoices, password resets, support tickets and signed contracts. Cold outreach is the one activity in your business with a predictable complaint rate. If a campaign goes badly, complaints and bounces attach to the reputation your billing email depends on, and there is no undo button. That damage takes weeks of clean sending to repair.

So you separate the two. Transactional and human mail stays on the primary. Cold campaigns go out from throwaway lookalike domains you can retire without pain. That separation is the entire argument for a dedicated sending domain, and it is standard practice across every outbound team I've worked with.

One thing to be clear about: Google and Microsoft do not ban cold email. They prohibit unsolicited bulk mail and they enforce published sender requirements. Google's and Microsoft's bulk sender rules require SPF, DKIM and DMARC, one-click unsubscribe, and a Postmaster Tools spam rate under 0.30% (Google recommends staying below 0.10%). Those rules apply at 5,000 or more messages a day to Gmail. Targeted, relevant, low volume outreach from a properly authenticated domain is a compliance problem you can solve, not a prohibited activity.

Where should I buy domains for cold email?

Buy from a mainstream registrar with transparent renewal pricing and WHOIS privacy included at no extra charge. Porkbun and Cloudflare Registrar are the two I reach for. Avoid registrars that advertise a cheap first year and quietly triple the renewal, because you'll hold these domains for years. Here is what I could verify on each registrar's own pages today. Several refused automated requests or load their price tables with JavaScript, so those cells say so rather than guessing.

Two footnotes. First, I'd rather leave a cell empty than publish a number I cannot point at. Check the price at checkout before you buy fifteen of anything. Second, Cloudflare Registrar has a real constraint: every domain registered there uses Cloudflare nameservers, and their documentation states you will not be able to change to another DNS provider's nameservers while using Cloudflare Registrar. If your team runs DNS elsewhere, that is a reason to register sending domains somewhere else.

WHOIS privacy

Turn it on. Public WHOIS records on a batch of freshly registered lookalike domains hand a curious recipient a tidy list of every other domain you own, and they attract scrapers. Registrars that charge extra for privacy are raising the real per domain price, so factor that in.

What TLD is best for cold email?

.com, in almost every case. It is the default expectation for a US B2B company, it never looks like a shortcut, and it costs about the same as the alternatives. .net and .co are workable second choices if the .com variants you want are gone. Everything else is a judgment call you don't need to make.

Nobody publishes a list of blocked TLDs, and any article claiming a given extension is "blacklisted" is inventing it. The truth is duller: some newer TLDs carry a heavier historical abuse load because they're cheap to register in bulk, and filters weigh domain reputation heavily. A brand new domain has no reputation of its own yet. .com is the lowest risk default, and at eleven dollars there is no reason to gamble.

Country codes are their own trap. A .io or .ai reads fine for a dev tool, but a country code your prospect does not associate with your company adds a second of doubt at exactly the wrong moment.

How to pick lookalike names that don't read as spam

The goal is a domain a prospect could plausibly believe is yours. If your company is Northwind Analytics on northwind.com, trynorthwind.com or northwindhq.com pass without comment. Character strings, hyphen stacks and numbers do not.

Keep names short enough to fit comfortably in a From line, and say each one out loud once. If it sounds awkward on a call, it looks awkward in an inbox.

Should I buy aged domains for cold email?

Usually no, at least not from a marketplace that specializes in selling them to cold emailers. Age genuinely correlates with trust, but you are buying a history you cannot fully inspect, and a domain previously used for spam or an unrelated adult or gambling site can arrive with reputation baggage no warm-up will fix.

If you do go to the aftermarket, do your homework. Pull the domain's history in the Wayback Machine, check it against public blocklist lookups, and look at what the prior WHOIS records show. Aftermarket pricing is also wildly inconsistent, so before you overpay for a name someone else already owns, check what comparable names have actually sold for and treat that as your ceiling. My honest read: a fresh .com you warm properly for two to four weeks beats a mystery five year old domain most of the time. We go deeper into the tradeoff in our piece on how much domain age really matters.

Can I use a subdomain for cold email?

You can, and outbound.yourcompany.com is better than sending from the root domain. But it is not real isolation. Reputation at the organizational domain level can still be affected, and your root DMARC policy applies to the subdomain unless you set a separate one. For risky volume, separate registered domains are safer.

Where subdomains do make sense: click tracking and transactional product mail, the cases where you want inheritance from the parent brand rather than separation from it.

Redirect every sending domain to your main site

This takes five minutes and gets skipped constantly. A prospect who gets mail from trynorthwind.com will sometimes paste the domain into a browser. If it serves a registrar parking page, you look like a scam. Set a 301 from every sending domain (and its www host) to your primary website, ideally with a UTM parameter so you can see the traffic.

Most registrars, Porkbun included, bundle URL forwarding, so this is two clicks in the DNS panel. Do it the day you buy the domain, not the week you launch.

The DNS records to publish before the first send

Nothing sends until these resolve. Buy the domain, connect the mailbox provider, then work down this list. Our walkthrough of SPF, DKIM and DMARC setup for cold email has the exact record syntax.

After DNS propagates, warm the domain before you touch a real list. The convention among operators is two to three mailboxes per sending domain, roughly two to four weeks of warm-up, and a cap of about 20 to 50 cold sends per day per warmed mailbox. Our domain warm-up walkthrough covers the ramp schedule, and automatic warm-up handles the daily mechanics for you.

What this actually costs to run

Say you want 200 sends a day. At 2 mailboxes per domain and 40 sends per mailbox, that's roughly 3 domains and 6 mailboxes. Domains are the rounding error: at Porkbun's listed $11.08, three .com domains run about $33 a year. Mailboxes are the real line item, at $7.00 per user per month for Google Workspace Business Starter on an annual commitment or $7.00 per user per month for Microsoft 365 Business Basic on annual, so six mailboxes is about $42 a month.

The sending layer sits on top. ColdMailer connects unlimited SMTP and IMAP mailboxes on the Pro plan at $49 a month flat, rotates sends across them, and handles warm-up and AI personalization. We don't sell domains or mailboxes, so buy those wherever the pricing above makes sense and point them at us. If you're mapping the whole stack, the cold email infrastructure overview shows how domains, mailboxes, inbox rotation and your SMTP sender connect. There's a starter tier at 100 emails a month with one SMTP account if you want to test the setup on a single domain before you buy the rest.

The buying checklist

1. Pick three or four lookalike .com variants of your brand, no hyphens, no numbers.
2. Check them at a registrar with flat renewal pricing and WHOIS privacy included.
3. Register, enable privacy, and skip the upsells you don't need.
4. 301 each domain plus its www host to your main site the same day.
5. Connect mailboxes, then publish MX, SPF, DKIM, DMARC and a tracking CNAME.
6. Warm for two to four weeks, then start at low volume and watch your spam rate in Postmaster Tools.

Domains are cheap and mistakes are not. Spend twenty minutes on names and DNS now, and your outbound program never has to touch the domain your invoices go out from.