Identity
54
B
f5.com
Posture Score: 80/100
Scanned May 8, 2026 at 4:01 PM UTC
Attack Surface
88
Reputation
99
Identity Findings
Weak DKIM RSA key (~1296 bits) for selector 'selector1'
RSA keys shorter than 2048 bits are considered weak. Current key is approximately 1296 bits.
💡 Generate a new 2048-bit (or larger) RSA key pair and update the DKIM record.
Weak DKIM RSA key (~1296 bits) for selector 'k1'
RSA keys shorter than 2048 bits are considered weak. Current key is approximately 1296 bits.
💡 Generate a new 2048-bit (or larger) RSA key pair and update the DKIM record.
Weak DKIM RSA key (~1296 bits) for selector 's2'
RSA keys shorter than 2048 bits are considered weak. Current key is approximately 1296 bits.
💡 Generate a new 2048-bit (or larger) RSA key pair and update the DKIM record.
Generic ISP PTR hostname: esa.hc5801-97.iphmx.com
The PTR record for 139.138.58.65 appears to be a generic ISP hostname, which can harm deliverability.
💡 Set a meaningful PTR record like mail.f5.com
Generic ISP PTR hostname: esa.hc5801-97.iphmx.com
The PTR record for 68.232.154.38 appears to be a generic ISP hostname, which can harm deliverability.
💡 Set a meaningful PTR record like mail.f5.com
Generic ISP PTR hostname: esa.hc5801-97.iphmx.com
The PTR record for 139.138.58.65 appears to be a generic ISP hostname, which can harm deliverability.
💡 Set a meaningful PTR record like mail.f5.com
Generic ISP PTR hostname: esa.hc5801-97.iphmx.com
The PTR record for 68.232.154.38 appears to be a generic ISP hostname, which can harm deliverability.
💡 Set a meaningful PTR record like mail.f5.com
ARC support not detected
No evidence of ARC (Authenticated Received Chain) support on MX servers. Forwarded messages may lose authentication.
💡 Consider enabling ARC signing on your mail servers to preserve authentication through forwarding.
Shared IP 139.138.58.65 used by multiple MX servers
The IP 139.138.58.65 is shared across 2 MX hostnames, reducing redundancy.
💡 Use unique IP addresses for each MX server for better redundancy.
Shared IP 68.232.154.38 used by multiple MX servers
The IP 68.232.154.38 is shared across 2 MX hostnames, reducing redundancy.
💡 Use unique IP addresses for each MX server for better redundancy.
Slow DNS response from pdns130.f5.com: 2211.3ms
The nameserver pdns130.f5.com responded in 2211.3ms, exceeding the 500ms threshold.
💡 Investigate network latency or performance issues on pdns130.f5.com.
Slow DNS response from pdns151.f5.com: 2191.2ms
The nameserver pdns151.f5.com responded in 2191.2ms, exceeding the 500ms threshold.
💡 Investigate network latency or performance issues on pdns151.f5.com.
Very low TTL on A record: 30s
The A record has a TTL of 30s or less (below 300s).
💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.
SPF record is valid
The SPF record is properly configured with valid syntax and within lookup limits.
DKIM cryptographic configuration is compliant
No RFC 8301 compliance issues detected in DKIM key configuration.
MX records are valid
All MX records are properly configured.
MTA-STS and TLS-RPT are properly configured
MTA-STS policy is enforced and TLS reporting is configured.
SMTP security checks passed
No open relay, VRFY/EXPN, or banner disclosure issues detected.
SMTP RFC 5321 compliance checks passed
The mail server accepts postmaster@ and abuse@ and uses a valid FQDN in EHLO.
IPv6 readiness is good
IPv6 records are present and properly configured.
STARTTLS downgrade resistance is adequate
STARTTLS is supported with modern TLS and protected by MTA-STS and/or DANE.
NS delegation is properly configured
All nameservers are responsive, consistent, and properly secured.
DKIM2 not detected
No DKIM key record with v=2 was found across common selectors. DKIM2 is an emerging standard and not yet widely deployed.
DMARC alignment: adkim=r, aspf=r
DKIM alignment is relaxed, SPF alignment is relaxed.
DMARC failure reporting: fo=1
Failure reports generated when any authentication mechanism fails.
DMARCbis np tag absent
The DMARC record does not include the np (non-existent subdomain policy) tag. Consider adding np=reject to protect non-existent subdomains under DMARCbis.
Deprecated DMARCbis tags found: ri
The DMARC record contains tags deprecated in DMARCbis: ri. Consider removing these for forward compatibility.
DMARCbis psd tag absent
The DMARC record does not include the psd (public suffix domain) indicator. Consider adding psd=n to explicitly identify this as an organizational domain.
No DANE/TLSA records found
DANE is not configured for any MX server. This is optional but provides strong certificate binding.
No BIMI record found
BIMI is not configured. Your brand logo will not display in supporting email clients.
Open mail ports on mx2.hc5801-97.iphmx.com
Detected open mail-related ports: 25
RFC 8058 one-click unsubscribe assessment
DKIM signing is configured. RFC 8058 compliance depends on List-Unsubscribe and List-Unsubscribe-Post headers being included in outbound messages and DKIM signatures.
MX IP network diversity
MX IPs span 2 different /16 networks, providing good diversity.
SOA record parameters
Serial: 12604, Refresh: 3600s, Retry: 900s, Expire: 1209600s, Min TTL: 3600s
Authorized certificate authorities
CAA records restrict certificate issuance to: amazon.com, comodoca.com, digicert.com, entrust.net, letsencrypt.org, pki.goog, sectigo.com
Attack Surface Findings
DNS ANY query returns 49 record(s)
The DNS server responds to ANY queries with 49 record(s), creating significant DNS amplification risk.
💡 Configure the DNS server to refuse or minimize ANY query responses per RFC 8482.
Domain enumerability: medium
The domain has moderate enumerability. CT logs and DNS records reveal significant information about the domain structure.
💡 Restrict zone transfers, use NSEC3 instead of NSEC, consider wildcard certificates to reduce CT log exposure, and implement rate limiting on DNS queries.
DNSSEC is not enabled
No DNSKEY or DS records were found. DNS responses are not cryptographically authenticated.
💡 Enable DNSSEC by generating DNSKEY records and publishing DS records at the registrar.
No internal information leakage detected
No non-routable IP addresses or internal references were found in public DNS records.
No email autodiscovery endpoints detected
No Microsoft Autodiscover, Mozilla Autoconfig, or email SRV records were found.
14 subdomain(s) discovered for f5.com
Subdomains were enumerated via Certificate Transparency logs, DNS wordlist brute-forcing, and DNS record analysis.
0 certificate(s) found in CT logs
Certificate Transparency logs contain 0 certificate(s) for f5.com and its subdomains. Each certificate reveals subdomain names.
Reputation Findings
HSTS enabled but missing preload directive on f5.com
Strict-Transport-Security: max-age=31536000
💡 Add the "preload" directive to the HSTS header and submit the domain to hstspreload.org.
security.txt present
Found security.txt at https://f5.com/.well-known/security.txt.
TLS certificate valid for 213 days
Certificate for f5.com expires on 2026-12-07.
Certificate issued by Sectigo Public Server Authentication CA OV R40
The certificate for f5.com is issued by a third-party CA.
Signature algorithm: rsa-sha256
The certificate for f5.com uses an acceptable signature algorithm.
RSA key: 2048 bits
The certificate for f5.com uses an adequate RSA key of 2048 bits.
SCTs present in certificate
The certificate for f5.com contains Signed Certificate Timestamps.
No weak ciphers detected
No known weak cipher suites detected on f5.com.
Google Safe Browsing DNS check — no flag detected
DNS-based Safe Browsing lookup returned no results. Full verification requires the Google Safe Browsing API key.
Abuse contact lookup failed
Could not query abuse contact information.
PhishTank — API key required
PhishTank phishing database check requires an API key.
Sender Score — API key required
Sender Score reputation check requires an API key.
Cisco Talos — API key required
Cisco Talos IP reputation check requires an API key.
Could not connect to webmail.f5.com
HTTPS request to https://webmail.f5.com failed or timed out.
WHOIS lookup failed
Could not retrieve WHOIS data for f5.com.
Dependency Chains
DMARC Authentication Chain (SPF)
DMARC uses SPF to verify that emails come from authorized servers
SPF Record
SPF record found and configured
→
DMARC Policy
DMARC policy: reject
DMARC Authentication Chain (DKIM)
DMARC uses DKIM to verify that emails have not been tampered with
DKIM Signature
DKIM signature missing
→
DMARC Policy
DMARC policy: reject
⚠️ DKIM signature is missing. DMARC relies on DKIM to verify email integrity and prevent tampering. Without DKIM, DMARC alignment will fail for cryptographic verification.
Mail Server Identity: mx2.hc5801-97.iphmx.com
PTR record proves mail server legitimacy
MX: mx2.hc5801-97.iphmx.com
Mail server at 139.138.58.65
→
PTR Record
Reverse DNS: esa.hc5801-97.iphmx.com
Mail Server Identity: mx1.hc5801-97.iphmx.com
PTR record proves mail server legitimacy
MX: mx1.hc5801-97.iphmx.com
Mail server at 139.138.58.65
→
PTR Record
Reverse DNS: esa.hc5801-97.iphmx.com
Mail Server Reputation: mx2.hc5801-97.iphmx.com
RBL check ensures server is not blacklisted
MX: mx2.hc5801-97.iphmx.com
Mail server at 139.138.58.65
→
RBL Status
Not blacklisted
Mail Server Reputation: mx1.hc5801-97.iphmx.com
RBL check ensures server is not blacklisted
MX: mx1.hc5801-97.iphmx.com
Mail server at 139.138.58.65
→
RBL Status
Not blacklisted
Enforced Encryption Chain
MTA-STS enforces TLS encryption to prevent man-in-the-middle attacks
TLS Support
Mail servers support TLS encryption
→
MTA-STS Policy
Mode: enforce
Brand Identity Chain
BIMI displays your logo in email clients, but requires DMARC enforcement
DMARC Enforcement
DMARC policy: reject
→
BIMI Record
BIMI not configured
⚠️ BIMI record is missing. Even with DMARC enforcement, you need to configure BIMI to display your brand logo in supported email clients.
TLS Monitoring Chain
TLS-RPT provides reports about TLS connection failures
TLS Support
Mail servers support TLS encryption
→
TLS-RPT Reporting
TLS failure reporting configured
Security Checks
MX Records
✓
SPF Record
✓
DKIM Record
✗
DMARC Policy
✓
BIMI Record
✗
CAA Records
✓
DNSSEC
✗
MTA-STS
✓
TLS-RPT
✓
Embed Badge
Display your domain's security grade on your website or README:
<img src="https://scan.ractermx.com/badge/f5.com.svg" alt="Email Security Grade">
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