Should You Use a Separate Domain for Cold Email?
inboxy team · · 3 min read
Why not send from your main domain?
Inbox providers like Gmail and Outlook judge every sending domain on its reputation. Cold email carries more risk than normal email: some addresses bounce, some people mark you as spam, and few recipients engage. If that happens on your main domain, the damage spreads to everything else you send from it, including invoices, password resets, support replies and your team's everyday email.
A separate domain works like a firewall. If it gets into trouble, you pause it, fix the cause or replace it, and your main domain is never affected.
What should the separate domain look like?
- A close variation of your brand, so prospects recognise you: getacme.com, tryacme.com, acmehq.com, useacme.com.
- A .com where possible, or your country's main domain ending. Cheap novelty endings are more often abused by spammers and start with less trust.
- Redirected to your main website, so anyone who visits the domain lands somewhere real.
- Not too similar to someone else's brand. Lookalikes of other companies' domains can be treated as phishing.
How many domains do you need?
Put two or three mailboxes on each domain and send 30 to 50 cold emails per mailbox a day. So 500 emails a day needs about 13 mailboxes across 5 or 6 domains. Our guide on how many mailboxes you need has the full formula and worked examples.
How do you set a new domain up properly?
- Buy the domain a couple of weeks before you plan to send. Brand-new domains start with no history.
- Create mailboxes on a reputable provider such as Google Workspace.
- Publish SPF, DKIM and DMARC. Gmail, Yahoo and Microsoft now expect all three. See our setup guide.
- Set up the redirect to your main website.
- Warm up every mailbox for two to four weeks before campaigns. See how long warmup takes.
- Test placement with a free inbox placement test before your first send.
Is using a separate domain deceptive?
No, as long as the domain clearly belongs to your company, the sender is a real person at your company, and your emails say who you are. It is standard practice for outbound teams. What you must not do is hide who is sending or impersonate another business.
Skip the setup
inboxy creates Google Workspace mailboxes on your cold email domains with SPF, DKIM and DMARC already configured, connects them to your sequencer for free and keeps them warm, at a flat $3 per mailbox a month. See pricing.
quick answers
Can I send cold email from my main domain?
You can, but you shouldn't. If cold email damages its reputation, your invoices, support replies and team email can start landing in spam too. Use separate lookalike domains instead.
How many mailboxes should I put on one domain?
Two or three. More than that concentrates risk: a single spam-complaint wave would hit all of them at once.
Should the cold email domain redirect to my website?
Yes. Redirect every sending domain to your main website so prospects who check the domain land on your real site.
Do I need SPF, DKIM and DMARC on the new domain?
Yes. Gmail, Yahoo and Microsoft expect all three, and unauthenticated mail is the first thing their filters punish.
How long before I can send from a new domain?
Warm each new mailbox for two to four weeks, then ramp up slowly. Check with an inbox placement test before your first campaign.
