DNS Gurus

SSL Verification Bypassed

The server's SSL certificate could not be verified. The analysis was completed using insecure mode. Data may be less reliable.

Reason:

Hostname Mismatch - certificate is issued for reroute443.microsoft.com, not for mail.microsoft.is

Cached · just now
76/100 SECURITY SCORE

Certificate Information

Subject
C=US, ST=WA, L=Redmond, O=Microsoft Corporation, CN=reroute443.microsoft.com
Issuer
C=US, O=Microsoft Corporation, CN=Microsoft Azure RSA TLS Issuing CA 03
Valid From
November 07, 2025
Valid Until
May 06, 2026 129 days
Public Key
RSA 2048 bit Adequate
Signature Algorithm
SHA384-RSA
SHA-256 Fingerprint
13:3F:20:22:CE:8D:2B:A6:73:0E:42:EC:78:A9:03:D6:18:3B:F3:A3:E3:02:2B:EE:2A:5B:E3:75:FA:4E:30:42
Alternative Names
1 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
Missing
Not configured
X-Frame-Options
Missing
Not configured
X-Content-Type-Options
Missing
Not configured
Referrer-Policy
Missing
Not configured
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
  • • Add X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking
  • • Add X-Content-Type-Options: nosniff
  • • Add Referrer-Policy header (recommended: strict-origin-when-cross-origin)
  • • Consider adding Permissions-Policy to control browser features

CAA Records (Certificate Authority Authorization)

CAA Records
Configured (Restricts certificate issuance)
Current Issuer
Not Authorized (Potential misconfiguration)
CAA Issues
  • • CRITICAL: Current certificate issuer 'C=US, O=Microsoft Corporation, CN=Microsoft Azure RSA TLS Issuing CA 03' is NOT authorized by CAA records. Authorized CAs:
Recommendations
  • • Consider using critical flag (flags=128) for stricter CAA enforcement
  • • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts

Subject Alternative Names

1 domain
reroute443.microsoft.com