Email Diagnostics

Email & Domain Diagnostics

Check MX routing, SPF, DKIM, DMARC, and DNS health for any domain — all in one place.

Custom DKIM selector (optional):

MX routing

SPF policy

DKIM signing

DMARC policy

DNS records

What this tool checks

Enter any domain above to run a full email diagnostic.

Verify which mail servers are configured to receive email for your domain, ordered by priority.

Check your Sender Policy Framework record to ensure only authorised servers can send mail on your behalf.

Probe common DKIM selectors to verify email signing keys are published and discoverable.

Check your DMARC record and policy level — none, quarantine, or reject — to prevent domain spoofing.

View IP addresses and nameservers to confirm the domain's DNS is healthy and resolves correctly.

Get actionable warnings for common misconfigurations — missing records, duplicate SPF, weak DMARC policy.

UnderHost includes business email, cPanel mail, and full DNS management with all hosting plans.