Never send from your main domain.
Cold email puts the reputation of the domain it’s sent from at risk. Send it from a second domain, so one bad week can’t hurt your company inbox.
Same person, two From lines
From your main domain
Sara Khan <sara@brightpath.co.uk>
Shares a name with your invoicesFrom a second domain
Sara Khan <sara@getbrightpath.co.uk>
Keeps the risk away from themOn this page
Reputation follows the domain
Gmail, Outlook and Yahoo judge mail partly by the domain it comes from. SPF, DKIM and DMARC tie each email to that domain, so bounces and spam reports count against it.
Cold email is the riskiest mail you send. People didn’t ask for it, some will mark it as spam, and old lists bounce. If it goes out from your main domain, a bad week can push your invoices, proposals and replies to customers into spam too.
A second domain keeps that risk away from them. It doesn’t cost much, and if it ever gets a bad name, your company inbox is untouched.
The teardown
The same sender, before and after. Tap or swipe the card to flip it.
How to set it up
Buy a second domain that’s clearly yours.
Add a short word to your name, like get, try or hq: getbrightpath.co.uk. Don’t pick anything that could pass for another company.
Send its website to your main site.
Set the new domain to redirect to your real website, so anyone who checks it lands somewhere they recognise.
Set up SPF, DKIM and DMARC.
Your email provider gives you the records to add. Then run the new domain through our domain check.
Create two or three inboxes.
Use real names, like sara@, not sales@. Spread your sending across them.
Warm them up before you send.
Let a warm-up tool send and answer mail from the new inboxes for a few weeks first. All five tools we review include warm-up.
Watch the numbers.
If bounces or spam reports climb, stop and clean your list before you send more.
Find a sending domain
Type your main domain. We’ll suggest second domains and check whether each one already has DNS records.
“No DNS found” usually means the domain is free, but only a registrar can say for sure. The check runs in your browser and asks Google Public DNS.
What Gmail, Yahoo and Outlook require
The big inboxes publish their rules. These are the main ones, read on each provider’s own page on 30 October 2026.
| Rule | Gmail | Yahoo | Outlook.com |
|---|---|---|---|
| Who it’s for | Every sender, with more rules from 5,000 emails a day to Gmail | Every sender, with more rules for bulk senders | Domains sending more than 5,000 emails a day |
| SPF and DKIM | SPF or DKIM for everyone. Both from 5,000 a day | SPF or DKIM for everyone. Both for bulk senders | Both |
| DMARC | From 5,000 a day. A policy of p=none is enough, and the From domain must align with SPF or DKIM | For bulk senders, at least p=none, and it must pass | At least p=none, aligned with SPF or DKIM |
| Spam reports | Below 0.3% for everyone. Google suggests staying under 0.1% | Below 0.3% | Not part of this rule |
| One-click unsubscribe | For marketing messages, from 5,000 a day | For bulk senders, and unsubscribes honoured within 2 days | Not part of this rule |
Most cold senders stay well under 5,000 emails a day per domain. Set up all three records anyway: it takes minutes, and the rules have only got stricter. Outlook.com now rejects mail from high-volume domains that fail its checks, with the error “550 5.7.515”.
- Google, Email sender guidelines. The rules apply from 1 February 2024.
- Yahoo, Sender Hub best practices.
- Microsoft, Outlook’s new requirements for high-volume senders, updated 30 April 2025. Applies to outlook.com, hotmail.com and live.com addresses.
Before you send
- A second domain that’s clearly yours
- Its website redirects to your main site
- SPF, DKIM and DMARC pass our domain check
- Two or three inboxes, warmed up first
- A clean list, with bounces and spam reports watched
Your emails still need to follow UK rules. In plain English: who you can cold email in the UK. Not legal advice.
