DNS Gurus
Cached · just now
93/100 SECURITY SCORE

Certificate Information

Subject
CN=startmail.com
Issuer
C=US, O=Let's Encrypt, CN=R13
Valid From
December 16, 2025
Valid Until
March 16, 2026 73 days
Public Key
RSA 4096 bit Strong
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
02:B3:AE:E7:FD:B5:89:91:F3:AB:5F:70:1B:AF:35:6B:E4:01:9E:EA:BF:6F:9F:99:3A:A6:66:B7:97:AB:74:4F
Alternative Names
12 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=31536000
Content-Security-Policy
Weak
frame-ancestors
X-Frame-Options
Excellent
DENY
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
no-referrer
Permissions-Policy
Present
camera=(), geolocation=(), interest-cohort=(), microphone=(), midi=()
Recommendations
  • • Increase HSTS max-age to at least 1 year and add includeSubDomains
  • • Significantly strengthen CSP directives

CAA Records (Certificate Authority Authorization)

CAA Records
Configured (Restricts certificate issuance)
Current Issuer
Authorized (Matches CAA policy)
Authorized CAs
letsencrypt.org
Wildcard CAs
letsencrypt.org
Incident Reporting
Recommendations
  • • Consider using critical flag (flags=128) for stricter CAA enforcement