DNS Gurus
Cached · just now
87/100 SECURITY SCORE

Certificate Information

Subject
CN=mailbox.celseven.com
Issuer
C=US, O=Let's Encrypt, CN=R12
Valid From
November 15, 2025
Valid Until
February 13, 2026 44 days
Public Key
RSA 4096 bit Strong
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
0E:D0:75:E8:F3:9E:C7:E7:E8:D3:F6:F9:BB:EC:6C:F9:D2:C2:9F:3D:21:5A:54:2D:A3:6A:E3:09:B5:FB:8F:5B
Alternative Names
16 domains

Security Configuration

TLS Protocols
TLS 1.2 TLS 1.3
Forward Secrecy
Supported (Modern clients use PFS)

HTTP Security Headers

Status
Strict-Transport-Security
Present
max-age=15768000;
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
strict-origin
Permissions-Policy
Missing
Not configured
Recommendations
  • • Increase HSTS max-age to at least 1 year and add includeSubDomains
  • • Add Content-Security-Policy header to prevent XSS attacks
  • • Consider adding Permissions-Policy to control browser features

CAA Records (Certificate Authority Authorization)

CAA Records
Not Configured (Any CA can issue certificates)
CAA Issues
  • • No CAA records configured - any CA can issue certificates
Recommendations
  • • Implement CAA records to restrict which CAs can issue certificates for your domain
  • • This adds an extra layer of security against unauthorized certificate issuance
  • • Example: Add CAA record 'example.com. CAA 0 issue "letsencrypt.org"'
  • • Consider adding 'iodef' record to receive security incident reports