Free tool
DNS health checker
Check your domain's nameservers, redundancy, MX records and CAA records, and find the DNS problems that take websites and email offline.
What you get out of it
- Confirm your nameservers answer and are redundant.
- See where your email is delivered.
- Check who may issue certificates for your domain.
A one-off check is a snapshot. Add the domain to DomainGuard and it is watched: its uptime every five minutes on every plan, and on Starter and up every check here again each day, with an alert in the app when something important changes. What DomainGuard watches
What it checks
Email Authentication
DNS Health
Other free checkers
- Website & Domain ReportOne report on your email security, DNS, SSL, security headers, cookies, registration and reputation, with a link you can share with your IT provider.
- Email Security CheckerCheck SPF, DKIM, DMARC, MX, MTA-STS and TLS-RPT for your domain and find out whether your email can be spoofed or will land in spam.
- SPF CheckerCheck your domain's SPF record: whether it is valid, whether it stays under the 10-lookup limit, and how strictly it treats unlisted senders.
- DMARC CheckerCheck whether your domain has a DMARC record, what its policy is, and whether it protects your customers from email sent in your name.
- DKIM CheckerCheck whether your domain publishes DKIM keys for common mail providers, so receivers can verify your email is really from you.
- SSL CheckerCheck your website's SSL certificate: expiry date, trust chain, hostname coverage, TLS versions, HTTPS redirect and HSTS.
- Security Headers CheckerCheck your website's HTTP security headers (CSP, HSTS, X-Frame-Options and more) and cookie flags, with a fix for each one missing.
- Blacklist CheckerCheck whether the servers behind your domain are listed on the spam blocklists mail providers use to reject email.
- Domain Expiration CheckerCheck when your domain expires, who it is registered with, how old it is and who hosts the website, so a lapsed renewal never takes your site and email down.