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Free DNS & email security check
Can scammers send email as your business?
Free email and domain security check for Australian businesses. We test your SPF, DKIM and DMARC, plus DNSSEC, HTTPS and security headers. You get an instant grade, plain-English fixes and a PDF report.
- SPF
- DKIM
- DMARC
- MTA-STS
- DNSSEC
- HTTPS
- Headers
Reads public records only. Nothing is changed or stored.
Scanning
Checking your domain
- Finding name servers & DNSSEC
- Reading mail servers (MX)
- Testing SPF & counting lookups
- Looking for DKIM keys
- Checking DMARC policy
- Checking MTA-STS & TLS reporting
- Testing HTTPS & certificate
- Reading security headers
Your report
Security advisor
Your action plan & best practices
Raw DNS
All DNS records
Your next step
Want a card like this for your domain?
We fix every item in your report, setting up SPF, DKIM, DMARC, MTA-STS and DNSSEC properly for Microsoft 365, Google Workspace and more, then monitor your DMARC reports so nobody can send email as you.
What we check
Every record that protects your email and domain.
One scan covers the email authentication, DNS and website protections recommended by the Australian Cyber Security Centre.
strict-transport-security: max-age=31536000content-security-policy: default-src 'self'x-frame-options: DENYWhat do these checks mean?
SPF record
Who may sendLists the servers allowed to send email as your domain. We check there's exactly one record, that it ends in -all or ~all, and that it stays within the 10-lookup limit.
Example recordv=spf1 include:spf.protection.outlook.com -allDKIM signing
Proves it's really youDigitally signs your emails so receivers know they're genuine. We look for keys on common selectors, including Microsoft 365 and Google Workspace, and flag short keys.
Example recordselector1._domainkey → v=DKIM1; k=rsa; p=MIIB…DMARC policy
Blocks fakesTells the world what to do with fake email from your domain. We check your policy (none, quarantine or reject), coverage and reporting address.
Example recordv=DMARC1; p=reject; rua=mailto:dmarc@…Mail servers
Who receives your mailShows who handles your email, such as Microsoft 365, Google Workspace or Mimecast, and whether the domain should send email at all.
Example record0 yourbusiness-com-au.mail.protection.outlook.comMTA-STS & TLS-RPT
Encrypted deliveryForces encrypted delivery of email to you and reports problems, stopping attackers quietly downgrading your mail to plain text.
Example record_mta-sts → v=STSv1; id=20261026DNSSEC & CAA
Trusted DNS answersDNSSEC stops forged DNS answers redirecting your domain. CAA limits which certificate authorities can issue certificates for you.
Example recordDS 2371 13 2 9F3A… · CAA 0 issue "letsencrypt.org"HTTPS & certificate
Secure websiteChecks your website loads securely, the certificate is valid and not about to expire, and that http:// redirects to https://.
Example recordhttp:// → 301 → https:// · cert valid 74 daysSecurity headers
Protects visitorsLooks for HSTS, Content-Security-Policy, clickjacking protection and other headers that protect your visitors, plus version leaks.
Example recordstrict-transport-security: max-age=31536000Why it matters
Email spoofing is the easiest way into an Australian business.
Scammers don't need to hack you to pretend to be you. Without SPF, DKIM and an enforced DMARC policy, anyone can send an email that looks exactly like it came from your domain: a fake invoice to your clients, a "change of bank details" to your suppliers, or a password reset to your staff.
Business email compromise is one of the most costly cyber crimes reported to the Australian Cyber Security Centre. Getting these records right also helps your genuine emails reach the inbox.
FAQ
DNS & email security questions.
Need help reading your report? Our Australian team can walk you through it.
Talk to a Security Specialist →What is SPF?
SPF (Sender Policy Framework) is a DNS record that lists the servers allowed to send email for your domain. Receiving mail servers use it to spot emails that claim to be from you but come from somewhere else.
What is DKIM?
DKIM adds a digital signature to every email you send. The matching public key is published in your DNS, so receivers can confirm the email really came from you and wasn't changed on the way.
What is DMARC and which policy should I use?
DMARC tells receiving servers what to do with emails that fail SPF and DKIM, and sends you reports. Start with p=none to collect reports, then move to p=quarantine and finally p=reject for full protection against email spoofing.
Is this DNS check safe to run?
Yes. The checker only reads public DNS records and your website's public response headers, the same information any email server or browser sees. It doesn't log in, change anything or store your results.
Why does email authentication matter for Australian businesses?
Business email compromise and invoice fraud cost Australian businesses millions every year. SPF, DKIM and DMARC make it much harder for scammers to send emails that look like they came from your business, and they help your real emails reach the inbox.
Can Sentinels Cloud fix the issues for me?
Yes. Our Australian team sets up SPF, DKIM, DMARC, MTA-STS and DNSSEC for Microsoft 365, Google Workspace and other platforms, and monitors your DMARC reports. Book a free assessment or call 03 4239 0770.