Identity
59
B
harpercollins.com
Posture Score: 82/100
Scanned May 8, 2026 at 6:44 PM UTC
Attack Surface
88
Reputation
98
Identity Findings
Weak DKIM RSA key (~1296 bits) for selector 'selector2'
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.
Weak DKIM RSA key (~1296 bits) for selector 'cm'
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.
No MTA-STS record found
Without MTA-STS, mail transport encryption cannot be enforced and is vulnerable to downgrade attacks.
💡 Publish a _mta-sts TXT record and host a policy file at https://mta-sts.harpercollins.com/.well-known/mta-sts.txt
STARTTLS without MTA-STS or DANE protection
STARTTLS alone is vulnerable to downgrade attacks. Neither MTA-STS nor DANE is configured to enforce encryption.
💡 Deploy MTA-STS and/or DANE to protect against STARTTLS stripping attacks.
No CAA records found
No CAA records are configured. Any certificate authority can issue certificates for this domain.
💡 Add CAA records to restrict certificate issuance. Example: 0 issue "letsencrypt.org"
Void lookup: include:%{ir}.%{v}.%{d}.spf.has.pphosted.com
The mechanism include:%{ir}.%{v}.%{d}.spf.has.pphosted.com returns no records, wasting a DNS lookup.
💡 Remove mechanisms that reference non-existent domains.
No TLS-RPT record found
Without TLS-RPT, you will not receive reports about TLS negotiation failures.
💡 Publish a _smtp._tls TXT record (e.g. "v=TLSRPTv1; rua=mailto:tls-reports@harpercollins.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 205.220.170.48 used by multiple MX servers
The IP 205.220.170.48 is shared across 2 MX hostnames, reducing redundancy.
💡 Use unique IP addresses for each MX server for better redundancy.
NS TTL mismatch between parent and authoritative zone
The NS record TTL in the parent zone (~7194s) differs significantly from the authoritative zone (~21600s).
💡 Align NS record TTLs between the parent zone delegation and the authoritative zone.
DKIM cryptographic configuration is compliant
No RFC 8301 compliance issues detected in DKIM key configuration.
No deprecated DMARCbis tags present
The DMARC record does not use any tags deprecated in DMARCbis (pct, rf, ri).
MX records are valid
All MX records are properly 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.
NS delegation is properly configured
All nameservers are responsive, consistent, and properly secured.
DNS responses are consistent across all nameservers
All authoritative nameservers return consistent answers with proper AA flags.
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.
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 mxa-00596a01.gslb.pphosted.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
All MX IPs are in the same /16 network. Consider diversifying across networks for resilience.
SOA record parameters
Serial: 628, Refresh: 21600s, Retry: 3600s, Expire: 1728000s, Min TTL: 21600s
Attack Surface Findings
DNS ANY query returns 42 record(s)
The DNS server responds to ANY queries with 42 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.
4 subdomain(s) discovered for harpercollins.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 harpercollins.com and its subdomains. Each certificate reveals subdomain names.
1 email SRV record(s) found
Email service SRV records expose mail server configuration for automatic client setup.
Reputation Findings
HSTS enabled but missing preload directive on harpercollins.com
Strict-Transport-Security: max-age=7889238
💡 Add the "preload" directive to the HSTS header and submit the domain to hstspreload.org.
Missing security.txt
No security.txt found at https://harpercollins.com/.well-known/security.txt.
💡 Create a /.well-known/security.txt file per RFC 9116 with Contact, Expires, and optionally Encryption and Policy fields.
TLS certificate valid for 212 days
Certificate for harpercollins.com expires on 2026-12-06.
Certificate issued by GeoTrust TLS RSA CA G1
The certificate for harpercollins.com is issued by a third-party CA.
Signature algorithm: rsa-sha256
The certificate for harpercollins.com uses an acceptable signature algorithm.
RSA key: 2048 bits
The certificate for harpercollins.com uses an adequate RSA key of 2048 bits.
SCTs present in certificate
The certificate for harpercollins.com contains Signed Certificate Timestamps.
No weak ciphers detected
No known weak cipher suites detected on harpercollins.com.
Domain valid for 340 days
Domain harpercollins.com expires on 2027-04-14.
Domain transfer and delete locks enabled
Domain harpercollins.com has clientTransferProhibited and clientDeleteProhibited locks.
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.harpercollins.com
HTTPS request to https://webmail.harpercollins.com failed or timed out.
WHOIS registration data
Registrar: MarkMonitor Inc. | Created: 1994-04-13 | Expires: 2027-04-14 | Updated: 2026-03-13
WHOIS privacy protection not detected
Domain harpercollins.com does not appear to have WHOIS privacy protection. Registrant details may be publicly visible.
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: mxa-00596a01.gslb.pphosted.com
PTR record proves mail server legitimacy
MX: mxa-00596a01.gslb.pphosted.com
Mail server at 205.220.170.48
→
PTR Record
Reverse DNS: mx0a-00596a01.pphosted.com
Mail Server Identity: mxb-00596a01.gslb.pphosted.com
PTR record proves mail server legitimacy
MX: mxb-00596a01.gslb.pphosted.com
Mail server at 205.220.170.48
→
PTR Record
Reverse DNS: mx0a-00596a01.pphosted.com
Mail Server Reputation: mxa-00596a01.gslb.pphosted.com
RBL check ensures server is not blacklisted
MX: mxa-00596a01.gslb.pphosted.com
Mail server at 205.220.170.48
→
RBL Status
Not blacklisted
Mail Server Reputation: mxb-00596a01.gslb.pphosted.com
RBL check ensures server is not blacklisted
MX: mxb-00596a01.gslb.pphosted.com
Mail server at 205.220.170.48
→
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
MTA-STS not configured
⚠️ MTA-STS policy is missing. Even with TLS support, you lack the enforcement layer that prevents attackers from stripping encryption (downgrade attacks).
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-RPT not configured
⚠️ TLS-RPT is not configured. Without TLS reporting, you have no visibility into TLS connection failures that may be impacting email delivery.
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/harpercollins.com.svg" alt="Email Security Grade">
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