Domain Health Lab

Domain Health Lab

Domain & email diagnostics

Check your domain, email and website health in 30 seconds.

Scan DNS, email security, SSL, HTTPS and domain configuration for free.

The checks behind your score
Start with your domain

Run a health check.

Have a DKIM selector?

Free. No account required.

Public domains only

Checking public records… most scans finish in 5–15 seconds.

SSL DNS SPF DMARC Email Security Headers Domain Expiration

01 — The report

The details behind a healthy domain.

See what passed, what needs a closer look, and what couldn't be verified.

I.

Email authentication

SPF, DMARC, known DKIM selectors and mail servers. Understand how your domain identifies legitimate email.

Check email policies
II.

Website & security

Certificate validity, HTTPS redirects and security headers. See what a visitor's connection can tell you.

Inspect a certificate
III.

DNS & registration

Public DNS records, nameservers and registry dates. Check the configuration that keeps your domain connected.

Look up DNS records

02 — The toolkit

A closer look at one thing.

Focused checks for a specific question.

All 12 tools
Email

DMARC checker

Look up your DMARC record, understand none, quarantine and reject policies, and inspect alignment and reporting settings.

Email

SPF checker

Inspect SPF mechanisms, soft-fail and hard-fail policies, duplicate records and first-level includes for your domain.

Website

SSL certificate checker

Check a website certificate's trust, hostname, issuer, validity dates and negotiated TLS version.

DNS

DNS checker

Inspect your domain's public DNS records with plain-language explanations of addresses, aliases, mail servers and nameservers.

Website

Security header checker

Inspect HSTS, Content Security Policy, nosniff, Referrer Policy and Permissions Policy on your website's response.

Domain

Domain expiry checker

Find registry expiration dates, creation dates, registrar, status and nameservers using public RDAP registration data.

03 — Field notes

Understand before you change.

Practical reading for the configuration behind your email.

All guides
DMARC / Explained

DMARC, without the jargon

Understand policy, alignment and reports before changing how your domain handles unauthenticated email.

Read the guide SPF / Explained

What your SPF record actually does

Learn how authorized senders, includes and the DNS lookup limit affect your email configuration.

Read the guide DKIM / Explained

DKIM selectors and signatures explained

Find your selector, check its public key, and understand what a DNS lookup can and cannot prove.

Read the guide