Open
Cached
·
just now
93/100
SECURITY SCORE
Certificate Information
Subject
CN=*.fastmail.fm
Issuer
C=US, O=Let's Encrypt, CN=R13
Valid From
November 29, 2025
Valid Until
February 27, 2026
50 days
Public Key
RSA
2048 bit
Adequate
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
B6:EF:C8:BF:62:DE:41:D2:D7:25:48:5D:22:9F:09:5D:94:0F:42:81:8A:10:8E:25:96:3E:CA:03:CC:CA:48:FD
Alternative Names
Security Configuration
TLS Protocols
TLS 1.2
TLS 1.3
Forward Secrecy
Supported
(Modern clients use PFS)
HTTP Security Headers
Status
Strict-Transport-Security
Excellent
max-age=31536000; includeSubDomains; preload
Content-Security-Policy
Basic
default-src; script-src; style-src; +5 more
default-src 'self'; script-src 'self' 'unsafe-eval' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https://gravatar.com https://www.gravatar.com; frame-src 'self' https://play.libsyn.com; base-uri 'none'; form-action 'self' https://duckduckgo.com; frame-ancestors 'none';
X-Frame-Options
Excellent
DENY
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
strict-origin-when-cross-origin
Permissions-Policy
Present
accelerometer=(), ambient-light-sensor=(), battery=(), camera=(), display-capture=(), document-domain=(), encrypted-media=(), geolocation=(), gyroscope=(), keyboard-map=(), magnetometer=(), microphone=(), midi=(), navigation-override=(), payment=(), publickey-credentials-get=(), screen-wake-lock=(), sync-xhr=(), usb=(), xr-spatial-tracking=()
Recommendations
- • Improve CSP by adding more specific directives and removing 'unsafe-inline'
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