What this tool does
It checks MX routing, A/AAAA records, nameservers, SPF, DMARC, and common DKIM selectors for a domain.
Email Diagnostics
Email & Domain Diagnostics
Check MX routing, SPF, DKIM, DMARC, and DNS health for any domain — all in one place.
MX routing
SPF policy
DKIM signing
DMARC policy
DNS records
What this tool checks
Enter any domain above to run a full email diagnostic.
MX Records
Verify which mail servers are configured to receive email for your domain, ordered by priority.
SPF Record
Check your Sender Policy Framework record to ensure only authorised servers can send mail on your behalf.
DKIM
Probe common DKIM selectors to verify email signing keys are published and discoverable.
DMARC Policy
Check your DMARC record and policy level — none, quarantine, or reject — to prevent domain spoofing.
A / AAAA / NS
View IP addresses and nameservers to confirm the domain's DNS is healthy and resolves correctly.
Warnings
Get actionable warnings for common misconfigurations — missing records, duplicate SPF, weak DMARC policy.
Need email hosting or migration help?
UnderHost includes business email, cPanel mail, and full DNS management with all hosting plans.
Tool guide
Understanding Email & Domain Diagnostics
Email delivery depends on DNS. This diagnostic gives a clear view of the core records that decide whether a domain can send and receive mail reliably.
Who it helps
- Business owners whose contact forms or mailboxes are failing
- Administrators setting up hosted email
- Developers verifying DNS after a migration
Usage instructions
Enter the root domain. If you know a custom DKIM selector, add it before running the check.
Understanding the output
Missing MX records affect receiving mail. Missing SPF, DKIM, or DMARC can reduce trust and increase spam placement. Duplicate SPF records should be fixed immediately.
Why it matters for hosting
Mail DNS often breaks during hosting moves. Use this tool before and after changing nameservers or moving email to UnderHost, Google Workspace, Microsoft 365, or another provider.
