SPF, DKIM, and DMARC are email authentication protocols. When they’re set up correctly, inbox providers can confirm your email provider is allowed to send on behalf of your domain and your messages are less likely to be filtered.
These protocols are implemented by adding DNS records to your domain’s DNS configuration.
If you’re using a simple cold email setup (for example a dedicated outreach domain + Hunter Email Sequences), the best way to get the right DNS values is to follow your email provider’s official documentation.
👉 If you’re here because Hunter flagged an error in the Domain Health Check, go to this article instead: Fix SPF, DKIM, and DMARC issues detected by Hunter (Health Check)
Before you start: where to edit DNS records
You’ll add these records in the DNS provider where your domain’s DNS is hosted. Common examples:
your registrar (GoDaddy, Namecheap, etc.)
Cloudflare
Squarespace Domains
your hosting provider
If you’re not sure where DNS is managed, check your domain’s nameservers in your registrar or ask your admin team.
SPF, DKIM and DMARC implementation
Below are instructions on implementing SPF, DKIM, and DMARC depending on your email provider.
Set up SPF
SPF tells inbox providers which servers are allowed to send emails for your domain. It’s published as a TXT record on the root domain (example.com).
Provider guides:
How to verify SPF:
Set up DKIM
DKIM adds a cryptographic signature to your outgoing emails. It’s usually published as a TXT record on a selector hostname such as: selector._domainkey.example.com
Provider guides:
How to verify DKIM:
Set up DMARC
DMARC defines what inbox providers should do when SPF/DKIM checks fail and helps protect your domain against spoofing. It’s published as a TXT record at:_dmarc.example.com
Gmail/Google Workspace guide: link
Microsoft 365/Outlook guide:
How to verify DMARC
DNS changes can take time: DNS updates can take from a few minutes up to 24–48 hours depending on your DNS provider and TTL.
Where to find more information
If you want deeper background on how these protocols work, you can read our blog post:https://hunter.io/blog/spf-dkim-dmarc/