Why Should You Use a Lookalike Domain in Sales?

Why do I need to set up a new domain for sales outreach? Can’t I just use my primary domain?

This is a question we hear a lot during sales calls and customer onboarding.

Short answer: Technically, you can send sales emails from your main domain. But you might not want to, considering all the risks.

For a longer answer, keep reading to discover why setting up a lookalike domain makes perfect sense for every outbound email strategy.

What is a lookalike domain?

A lookalike domain is one that closely resembles your main brand domain (e.g. getaisdr.com vs aisdr.com) and belongs to the same owner.

You. 

Its ownership and intent that set lookalike apart from spoofing. 

Spoof domain names look like yours, but they’re created by malicious parties to impersonate you and cheat your customers. Meanwhile, lookalike domains are legit and ethical, as long as you use them for law-compliant outreach.

You can have more than one lookalike domain, using your brand name and variations:

• tryaisdr.com 
• helloaisdr.com
• buyaisdr.com

This comes back to the original question: 

Why should you use a lookalike domain?

Why use a lookalike domain for sales?

Lookalike domains are the “default mode” of sales outreach for several reasons. 

Protect your primary domain

Even if you’re serious about following the best cold email practices and reach out only to consenting people, there’s always a risk that your domain gets spam-tagged and blacklisted. 

In some cases, all it takes is a single complaint from a user who simply forgot they subscribed to your newsletter. In other cases, it’s the sheer volume of messages jumping from two or three to several hundred per day.

When a domain is blacklisted, all messages from it land in spam. If it’s your main domain, that means your purchase receipts, password resets, and payroll slips will all be quarantined and people won’t see your messages unless they go to spam.

In the worst-case scenario, your email provider might flag unusual activity and lock you out of your account entirely. That means no access, no replies, and potentially lost deals.

It can take weeks and thousands of dollars to reverse a blacklist and restore access to your mailbox, which is why it’s much better to have a stand-in domain take the hit. 

This lets your main domain continue running smoothly while you fix the problem.

Simplifying Mailbox Warm-up Checklist

A cold mailbox will send your emails straight to spam. This checklist outlines step by step how to warm up new mailboxes.

GET MY CHECKLIST

Improve deliverability

The nice thing about a lookalike domain is that it’s a clean slate. It’ll be judged by email providers based on its own behavior rather than any historical blips from your main domain.

With a new address, a sudden spike in activity won’t get you blocked if you do a proper domain warm-up. That same spike on a domain that’s already in use is more likely to trigger spam filters.

If you haven’t built a rock-solid sender infrastructure around your main domain, you can do it with a lookalike. Setting up a dedicated IP and custom Sender Policy Framework (SPF), among other things, can greatly improve deliverability. 

Test copy and sequences

You may want to A/B test your email copy and sending times to see what works best.

A downside to this approach is that “bad” versions are likely to get tagged as spam or deleted without opening. 

That can reflect badly on your main domain. But with a lookalike domain, you’re free to experiment. Custom sales domains are disposable: even if one gets blocked, you can simply shift to another.

Scale multichannel outreach

How many emails coming from the same address are treated as “too many” by email providers?

The published caps appear generous. Google, for example, permits up to 2,000 messages and 10,000 recipients per day. Microsoft 365 allows 30 emails per minute and 10,000 recipients per day.

This sounds good in theory, but in practice, your deliverability will slump long before you approach these thresholds. A safer rule-of-thumb number is no more than 50 emails per day per inbox. 

And even that can be too high. Some suggest a better max is 30 emails per day.

In short, companies use lookalike domains to protect their main domain, improve deliverability, experiment safely, and scale their cold email campaigns without a headache.

When should you consider using lookalike domains?

Lookalike domains aren’t just for big companies. Small teams adopt them as well when the situation calls for it. 

Here are a few typical scenarios.

You’re about to start outbound

A brand-new mailbox with no baggage will give you a head start. With a proper domain warm-up, you’ll avoid common beginner issues and build a good sender reputation. And if you make any mistakes later on, it’s only a lookalike domain that takes the hit; your main one will stand spotless.

You’re scaling cold outbound

Sending too many emails from the same address is risky. Providers look out for what they consider to be beyond “normal human activity” of about 100-150 messages per day (including to email addresses on the same domain) or 50 cold messages.

You can leverage AI to reach far more people than that. Just make sure to do that from a score of lookalike addresses so you don’t get blocked.

You’ve had deliverability issues in the past

Everyone makes mistakes, especially when working on a new task. 

Unfortunately, email providers are a bit strict and will judge a domain based on its whole history.

Yesterday’s missteps might cast a long shadow over today’s outreach. By setting up a new domain, you’ll effectively escape them and start fresh.

You can’t risk your primary domain

For many of us, our primary domain is much more than a mailbox. All our payments, Stripe and bank accounts, CRMs, and employee records are connected to it.

Such a valuable asset needs watertight protection, and a lookalike domain cushions it from most threats. If the lookalike gets throttled, support tickets will still reach your help desk, and receipts will land on financial dashboards.

In all these situations, the extra cost and effort of setting up a lookalike domain will pay off in no time.

Best practices for lookalike domains

Creating a lookalike domain largely follows the standard domain setup process, but there are a few critical distinctions you’ll want to keep in mind.

Keep branding close

Your “cousin” domain should look like it belongs on the same family tree. 

Make your brand name pop up at first glance and pair it with a short verb that prompts action:

• Try(brand)
• Get(brand)
• Join(brand)
• Meet(brand)

Good lookalike domain examples usually follow this formula, or pair the brand name with “hi”, “hello”, or “hey”.

Avoid extra hyphens, random numbers, and generic words:

• (brand)-official-mail
• (brand)-marketing-blast
• (brand)-14

These elements scream “bulk sender” and invite filtering. Stick to short, clean, brand-forward names to start on the right foot.

[Video]

Stand Out or Burn Out: Winning AI Sales Outreach in 2025

Get actionable strategies from AiSDR CEO Yuriy Zaremba on crafting campaigns that land meetings, not spam folders.

WATCH VIDEO

Use proper DNS setup

Once you register a domain name, it’s time to get a bit technical and set up a strong sender infrastructure to support your outreach. That generally includes:

• Dedicated IP – ensures no other sender can meddle with your reputation
• SPF – whitelisting the exact servers allowed to send mail on behalf of your new domain
• DKIM – adds a cryptographic signature that the recipient’s mailbox provider can verify
• DMARC – tells Gmail, Outlook, and friends what to do with messages that fail the SPF or DKIM test
• MX record – whitelists the servers that can receive mail on behalf of your domain, like SPF does for senders

With all these safety features and policies in place, your lookalike domain will enjoy robust protection that:

• Prevents email spoofing and fishing attacks on your customers
• Prevents malicious parties from impersonating you
• Improves deliverability as mail providers will treat your messages as verified and safe
• Lowers the likelihood of your messages triggering spam filters

That’s a rock-solid foundation for effective cold outreach.

Warm up gradually

Once all security protocols are set up, it’s time for mailbox warmup. 

Start by sending 5 messages per day to people you can rely on and who will open and write back (hint: friends, family, and close colleagues are great candidates here). You can even start by messaging your personal email addresses, though this will be a bit challenging to scale.

After the first week, bump the daily volume by roughly 10-20 percent while keeping your eye on the open, click, and complaint rates. By week 4, you should comfortably reach 50 messages a day without triggering any flags. 

While there are specialized agencies you can outsource this process to, using an automated warm-up solution will simplify this step and eliminate a lot of the headache without draining your budget.

Set up clear signatures and personas

Email accounts with filled-out profiles and signatures inspire trust from people and anti-spam algorithms alike. That’s why it makes sense to flesh out every outreach identity.

Give each mailbox a full name, a role, and a lightweight headshot or avatar. Keep signatures minimal: name, title, logo, and a single website link. Anything bigger than that might distract the reader and dilute your message.

Make sure that all personas sound on-brand. 

There’s no need to give each their own distinct voice, though: They might need to step in for each other. Your prospect shouldn’t feel the difference when you must continue an outreach sequence from a different domain.

Include unsubscribe links

This part might seem a bit counterintuitive: Why give people a chance to pull the plug on your messages?

The answer is simple – regulatory compliance.

CAN-SPAM in the US and GDPR in the EU both mandate a clear opt-out path for email senders. 

There’s simply no way around it if you target prospects in these countries, and unsubscribe links are the easiest path to compliance (although you don’t need to add them so long as you act promptly on any written unsubscribe requests). 

But even if your audience lives in more permissive locations, it still makes sense to include an unsubscribe link for a simple reason:

Imagine someone who no longer wants your messages, for whatever reason. They look for a way to opt out. When they can’t find one, they hit the “spam” button so they won’t get bothered again. 

Your sender reputation takes a blow in response. 

Having the unsubscribe link in your footer can go a long way to protect your standing with mail servers. To stay on their good side, try to avoid the common mistakes we’ll talk about next.

Common mistakes to avoid

While there’s no way to know in advance which email length or sending window will work best for you, there are certain missteps that can doom a campaign even before it kicks off. Here’s what to keep away from.

Creating suspicious-looking domains

Lookalike domains only work when they feel legit and clearly associated with the main brand. If your domain name appears suspicious to the email provider, it can get blocked even before you send any messages.

What makes a domain look suspicious? 

• Using a different top-level domain (TLD), such as .ai or .io, instead of .com (unless your main domain and branding uses such a TLD)
• Differentiating from your primary brand name through typos like a1sdr, aisdrr, or aizdr
• Replacing Latin characters with similar-looking Cyrillic or Greek letters

Changing a single letter in your brand name or shifting it to another TLD might both seem like easy fixes to differentiate your new domain while staying just a step away. Unfortunately, such naming practices scream “scam account” to Gmail and friends.

To avoid raising red flags, steer clear of one-letter fixes and stick to the same TLD. If you have .com for your main domain, use it for lookalikes as well.

Mass-blasting emails from day 1

A brand-new domain that suddenly sends hundreds of messages looks exactly like a spam bot. That’s why you need a gradual domain warm-up.

A possible ramp-up schedule could be this:

• Week 1: increase daily outreach from 5 to 15 emails, starting with 5 on Monday and adding 1-2 each day
• Week 2: from 15 to 25 emails
• Week 3: from 25 to 35 emails
• Week 4: from 35 to 45 emails

After week 4, you can comfortably send 50 emails per day from this mailbox.

Before each bump, you should check outbound performance metrics. If they plummet, something went wrong, so you should pause your outreach until you fix the problem, then resume.

Ignoring performance metrics

Sales outreach is like driving: Ignore the dashboard, and you’ll end up off course or without fuel.

In sales, keep an eye on these metrics:

• Hard bounce rate: ideally under 2% or under 4% for cold lists
• Spam complaint rate: should be under 0.1%, or 1 per 1,000 sends
• Unsubscribe rate: jumps often precede spam complaints
• Open rate: sudden drops signal deliverability issues
• IP/domain reputation (can be checked in Google Postmaster tools): must be “High” or “Medium,” otherwise your messages get filtered even before humans see them
• Blocklist status: should be “not listed”

When any metric leaves the safe zone, it’s better to pause sends and fix the root cause of the problem before resuming outreach.

The easiest way to track all key metrics and automate domain ramp-up is by using lookalike domain management tools.

Tools for creating and managing lookalike domains

Setting up and warming a lookalike domain manually might not be the best use of your team’s time. You can do it much faster with automated tools.

AiSDR

AiSDR helps you create domains during setup and start warming them up. The built-in proprietary AI triple-checks contact data to avoid bounces, rotates inboxes automatically, and keeps a running domain health score so you can spot problems before Gmail does. 

The real magic is buyer intent. AiSDR tracks website visitors, LinkedIn engagement, funding news, job changes, and 300-plus other signals, then lets its AI Strategist stitch those triggers into message cadences. The result is outreach that hits the mark, converting up to 10 times more leads into sales.

Need a human sanity check? Every account ships with a dedicated GTM engineer who tunes copy, domains, and deliverability dashboards alongside you.

AiSDR also boasts these advantages:

• Done-for-you email infrastructure, complete with SPF, DKIM, and DMARC
• Background warm-up, making your inbox “send-ready” in 3-5 days
• Custom AI configuration for outreach campaigns and automation of existing playbooks

Use case 

Spin up a fresh domain, warm it quietly, and launch hyper-personalized sequences the moment someone visits your pricing page or lands a new role, without ever logging out of your account.

Pricing

AiSDR has two pricing tiers. Explore starts at $900/month for 1,200 messages (LinkedIn + email) and includes ongoing warm-up, buyer-intent data, and a GTM engineer. The Grow tier ($2,500/month) unlocks bigger send volumes at a lower cost per email.

Warmy

Warmy’s entire job is to make brand-new (or bruised) domains look seasoned and trustworthy in the eyes of Gmail, Outlook, and other providers. The platform can drip up to 5,000 warm-up emails a day, spreading these across multiple mailboxes.

A live dashboard shows inbox‐placement, spam-folder rate, bounce-rate, and blacklist status so you can pull the plug the moment a metric turns red.

The platform comes with a few extra features:

• Blacklist scanner: daily checks on Spamhaus, MXToolbox, and dozens of RBLs
• Free SPF & DMARC generators so even non-technical founders can publish correct DNS
• One-on-one deliverability consultants when numbers dip

Use case 

Start warming up a lookalike domain two weeks before your first campaign, let Warmy keep the reputation climbing in the background, and watch the dashboard for green-light stats before flipping the switch.

Pricing

Warmy doesn’t disclose its pricing but offers a 7-day free trial.

Instantly

Instantly allows you to connect as many lookalike domains (or individual inboxes) as you like. The system auto-rotates sends, so no single address crosses the “looks weird” threshold.

You can purchase fresh sending domains inside the app or use additional features:

• A/Z testing (their take on A/B) that lets you trial different subject lines across domains
• An SISR sharding engine that swaps out IP blocks so campaigns keep humming 
• AI spam-word checker and inbox placement testing baked into the sequence builder

Use case 

A growth team running 10+ sequences can fan traffic across dozens of domains, compare performance side-by-side, and kill under-performers without touching DNS records.

Pricing 

The Growth plan comes at $37/month with unlimited accounts and warm-up for up to 2,000 emails. Heavy senders jump to Hyper Credits at $169/month for 100,000 emails.