Email DNS Record Builder

Build SPF, DKIM, and DMARC records in one place. This version is single-column, includes provider presets, copy buttons, recommendations, SPF lookup estimation, DMARC reporting help, and guidance on where to get DKIM values.

1. Domain

What to enter Recommended

Enter the exact domain you are configuring, like example.com. Do not include https://, slashes, or an email address.

Recommendation: Start with your root sending domain. If marketing or bulk mail uses a different subdomain, consider using a separate subdomain like mail.example.com for better isolation and reporting.

2. Provider preset

How to use Faster setup

Pick your mail provider to prefill common SPF values and DKIM selector suggestions. You can still edit everything manually.

3. SPF record

What SPF is Watch lookup limit Recommended

SPF tells receiving mail systems which servers are allowed to send mail for your domain. Keep SPF as short as possible. The practical processing limit is 10 DNS lookups.

Recommendation: Use -all once you're confident the record is complete. Use ~all only during a short transition or testing period.

4. DKIM record

What DKIM is Where to get it Recommended

DKIM adds a cryptographic signature to outbound email so receiving systems can verify it was sent by an authorized source and was not altered in transit.

Where the DKIM info comes from

  • Microsoft 365: Defender DKIM settings
  • Google Workspace: Admin Console → Apps → Google Workspace → Gmail → Authenticate Email
  • SendGrid: Settings → Sender Authentication
  • Proofpoint: Domains → Configure DKIM

What you usually receive

  • A selector like selector1 or google
  • Either a TXT public key or a CNAME target
  • Instructions from the mail provider for exactly what DNS record to publish
Recommendation: Enable DKIM in your mail platform first, then copy the exact selector and target/public key it provides. If the provider offers 2048-bit DKIM, use that unless they document otherwise.

5. DMARC policy

What DMARC is How to enter it Recommended rollout

DMARC tells receiving mail systems what to do when SPF or DKIM checks fail, and where to send aggregate reports. It is the policy layer that ties SPF and DKIM together.

Recommended rollout

  • Start with p=none to monitor
  • Move to p=quarantine after validation
  • Move to p=reject when all senders are aligned

Reporting advice

  • Create a real mailbox like dmarc@yourdomain.com
  • Review reports regularly, especially after changes
  • Use a mailbox or service you will actually monitor

6. Recommendations

Best practice Before publishing

These recommendations are general and safe defaults for most organizations. Adjust them based on your actual sending systems.

Recommended defaults

  • Use only the SPF includes you truly need
  • Enable DKIM for every outbound platform
  • Use a dedicated DMARC mailbox
  • Publish DMARC only after SPF and DKIM are working

Common mistakes to avoid

  • Putting two SPF TXT records on the same host
  • Leaving old providers in SPF after migration
  • Using the wrong selector from the mail platform
  • Going straight to DMARC reject before testing

7. Generate records

Ready to build

Click generate to build DNS-ready values. The buttons stay above the output section as requested.

8. Output

Copy and paste into DNS

These are generated helper values. Always compare them against your provider's official setup instructions before publishing.

SPF record
SPF output will appear here.
DKIM record
DKIM output will appear here.
DMARC record
DMARC output will appear here.