Lookalike domains for cold email: how to choose and set them up

A lookalike domain is a domain that is close to your brand name but is not your main one. If your company is acme.com, a lookalike might be getacme.com, tryacme.com or acmehq.com. Prospects recognise the name, the domain forwards to your real website, and cold email goes out from it instead of from the domain your business runs on.

Every campaign we run sends from four of them. This article covers why, how we choose the names, and what has to be true of each domain before it sends a single email.

Why you never send from your primary domain

Inbox providers judge a domain on everything it sends. Your main domain sends invoices, proposals, password resets, hiring email and replies to customers. Most of that mail is expected and welcome, and its reputation reflects it.

Cold email is the riskiest mail a company sends. It goes to people who have never heard of you, so it draws more spam reports and more bounces than anything else you do, even when it is done well. Send it from your main domain and those signals land on the same reputation your invoices depend on. One bad week can push a customer's reply into their spam folder, and repairing a primary domain is slow.

A lookalike domain separates the two. If something goes wrong with cold outreach, the damage stays on a domain that exists only for outreach. Your everyday mail carries on as before. That is the first of the six rules we do not bend: we never send from your primary domain.

How to pick the names

A good lookalike passes three tests. A prospect who reads it should recognise your company. Someone typing it should get it right the first time. And it should not look like an attempt to fool anyone.

The patterns we use most:

• A short prefix: get, try, use, with, meet, hello
• A short suffix: hq, team, app, mail used sparingly
• The same name on a different common extension, when the .com variants are taken

Some patterns we avoid:

• Misspellings of your own brand, such as acmme.com. They look careless at best and like phishing at worst.
• Hyphens and long strings of words, which read as throwaway domains.
• Unusual extensions with a poor reputation for abuse. A .com or the same extension as your main site is the safe default.
• Anything that imitates another company. A lookalike resembles your brand, never someone else's.

Check each candidate before you buy it. Look up whether it was registered before and what it was used for, because a domain with a spam history brings that history with it.

How many you need

The number follows from volume. We plan around three mailboxes per domain and 30 emails per mailbox per day. Twelve mailboxes cover a campaign of 10,000 emails in 28 days, so four domains carry them. The full arithmetic is in how many mailboxes and domains you need for 10,000 emails, and the reasoning behind 30 a day is in how many cold emails per day per mailbox is safe.

Splitting across four domains also spreads the risk. If one domain runs into trouble, it affects at most a quarter of the campaign, and the other three keep sending while it recovers. Putting all twelve mailboxes on one domain would make that domain a single point of failure. Giving every mailbox its own domain would multiply setup and renewals for little gain.

Forward every domain to your main site

Some prospects will look you up before they reply. They will type the domain from the email into a browser, or click the domain in your signature. If that leads to a blank page or a parked-domain ad, you lose them.

Set up a permanent redirect from every lookalike domain, with and without www, to your main website. Keep it simple: a 301 to your home page is enough. Do not build a separate website on the lookalike. The point is that the domain belongs to a real company and leads to it.

Authenticate each one properly

A lookalike domain needs the same records as any domain that sends mail, and it needs them before warmup starts:

• SPF, listing only the provider the mailboxes send through
• DKIM, generated in Google Workspace or Microsoft 365 and switched on
• DMARC, aligned with the From address, with reports going to an inbox someone reads
• MX records, so replies arrive and the domain looks like it receives mail

On a fresh sending domain nothing else sends mail, so we start DMARC at p=quarantine and move to p=reject once the reports are clean. Google, Yahoo and Microsoft all now expect authenticated, aligned mail from anyone who sends at volume, and the business inboxes you are writing to weigh the same signals. Our cold email deliverability checklist walks through each record in order.

Then the domain needs warmup. A lookalike registered yesterday has no history at all, and its mailboxes go through the same 14-day ramp as any other new address. We cover that in email warmup explained.

Who owns them

You should. The domains should be registered in your name, in a registrar account you control, from the first day. The same goes for the mailboxes and every login and recovery code.

This matters more than it sounds. Some services register sending domains in their own accounts and rent them to you. When you leave, the domains stay with them, along with the reputation your campaigns built. We register all four domains to you on day one, and when the campaign ends on day 44 they stay yours whether or not you keep working with us. Our domain and mailbox setup hands over every record and login in a shared vault.

Lookalike domains cost little to keep. If you stop sending for a while, keep paying the renewals. Reputation fades slowly, and a domain you return to after a quiet month is far easier to restart than a new one.

The risks of getting it wrong

Most problems with lookalike domains come from a handful of mistakes:

• Skipping the redirect. A prospect who checks your domain and finds nothing assumes the email was spam.
• Names that look deceptive. Misspellings and imitations draw complaints and can break a provider's terms of service.
• Buying a domain with a past. Old spam history follows the domain to its new owner.
• Missing or misaligned records. A domain that fails SPF, DKIM or DMARC is filtered no matter how good the copy is.
• Sending before warmup. A new domain sending full volume on day one looks exactly like the thing filters are built to stop.
• Too few domains for the volume. Overloading one domain to save a few dollars puts the whole campaign on one reputation.
• Not owning them. If the domains are not in your name, the reputation you built is not yours.

Each of these is cheap to avoid before launch and slow to undo after.

Summary

Lookalike domains keep your main domain out of cold outreach. Choose names a prospect would recognise, forward each one to your real site, authenticate it, warm it, and register it in your own name. We plan around four domains with three mailboxes each for a campaign of 10,000 emails.

If you would rather not register, configure and warm four domains yourself, start a Launch campaign with four lookalike domains included. They are bought in your name on day one.