Identity
82
B
mimecast.com
Posture Score: 87/100
Scanned May 9, 2026 at 4:31 AM UTC
Score History
Attack Surface
88
Reputation
91
Identity Findings
No DKIM records found
No DKIM records were found for any common selector. Email may not be authenticated.
💡 Configure DKIM signing and publish the public key at <selector>._domainkey.mimecast.com
MTA-STS is in testing mode
The MTA-STS policy is in testing mode and not actively enforcing TLS.
💡 Switch mode to "enforce" once TLS is confirmed working for all MX hosts.
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 91.220.42.231 used by multiple MX servers
The IP 91.220.42.231 is shared across 2 MX hostnames, reducing redundancy.
💡 Use unique IP addresses for each MX server for better redundancy.
Shared IP 195.130.217.231 used by multiple MX servers
The IP 195.130.217.231 is shared across 2 MX hostnames, reducing redundancy.
💡 Use unique IP addresses for each MX server for better redundancy.
No CAA iodef tag configured
No iodef tag is present in the CAA records. CA policy violation reports will not be sent.
💡 Add an iodef CAA record. Example: 0 iodef "mailto:security@example.com"
Very low TTL on MX records: 282s
2 MX records have a TTL of 282s or less (below 300s).
💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.
Very low TTL on TXT records: 282s
29 TXT records have a TTL of 282s or less (below 300s).
💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.
Very low TTL on SPF record: 282s
The SPF record has a TTL of 282s or less (below 300s).
💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.
Very low TTL on DMARC record: 282s
The DMARC record has a TTL of 282s or less (below 300s).
💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.
NS TTL mismatch between parent and authoritative zone
The NS record TTL in the parent zone (~7182s) differs significantly from the authoritative zone (~86400s).
💡 Align NS record TTLs between the parent zone delegation and the authoritative zone.
SPF record is valid
The SPF record is properly configured with valid syntax and within lookup limits.
SPF record length OK (39 bytes)
SPF record is within safe DNS packet size limits.
DKIM cryptographic configuration is compliant
No RFC 8301 compliance issues detected in DKIM key configuration.
All external report destinations authorized
External DMARC report destinations have valid authorization records per RFC 7489 §7.1.
Subdomains protected (sp=reject)
DMARC subdomain policy enforces quarantine or reject on unauthenticated subdomain mail.
MX records are valid
All MX records are properly configured.
2 MX records with 2 unique IPs
Multiple MX records provide mail delivery redundancy.
TLS-RPT report destinations are reachable
All TLS-RPT rua= URIs point to resolvable domains.
Meets bulk sender authentication requirements
Domain has SPF, DKIM, and DMARC — meeting Google/Yahoo 2024 bulk sender requirements for email authentication.
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.
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.
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.
Deprecated DMARCbis tags found: pct
The DMARC record contains tags deprecated in DMARCbis: pct. 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.
REQUIRETLS not advertised
The primary MX does not advertise REQUIRETLS (RFC 8689). This is an emerging standard — MTA-STS and DANE provide adequate TLS enforcement for most deployments.
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 service-alpha-inbound-a.mimecast.com
Detected open mail-related ports: 25, 587
Domain is IPv4-only
No AAAA records found for the domain, MX servers, or nameservers. The domain operates on IPv4 only.
RFC 8058 one-click unsubscribe assessment
No DKIM signing detected. RFC 8058 one-click unsubscribe requires DKIM-signed List-Unsubscribe headers.
MX IP network diversity
MX IPs span 2 different /16 networks, providing good diversity.
SOA record parameters
Serial: 1778244096, Refresh: 300s, Retry: 300s, Expire: 604800s, Min TTL: 86400s
Authorized certificate authorities
CAA records restrict certificate issuance to: pki.goog, amazonaws.com, letsencrypt.org, digicert.com
Attack Surface Findings
DNS ANY query returns 46 record(s)
The DNS server responds to ANY queries with 46 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.
All MX records resolve correctly
No dangling MX records detected — all MX hostnames resolve to valid IP addresses.
Explicit MX records present
The domain has explicit MX records — no implicit A-record fallback delivery.
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.
11 subdomain(s) discovered for mimecast.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 mimecast.com and its subdomains. Each certificate reveals subdomain names.
Reputation Findings
SMTP banner mismatch: eu-smtp-inbound-1.mimecast.com
The SMTP banner identifies as 'eu-smtp-inbound-1.mimecast.com' but the MX hostname is 'service-alpha-inbound-a.mimecast.com' and PTR resolves to 'service-alpha-inbound-b.mimecast.com'. Microsoft and other receivers flag this mismatch as suspicious infrastructure.
💡 Configure the SMTP server banner to match the MX hostname or PTR record (service-alpha-inbound-a.mimecast.com).
HSTS enabled but missing preload directive on mimecast.com
Strict-Transport-Security: max-age=31536000
💡 Add the "preload" directive to the HSTS header and submit the domain to hstspreload.org.
HSTS enabled with preload on webmail.mimecast.com
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
security.txt present
Found security.txt at https://mimecast.com/.well-known/security.txt.
TLS certificate valid for 202 days
Certificate for mimecast.com expires on 2026-11-27.
Certificate issued by DigiCert Global G2 TLS RSA SHA256 2020 CA1
The certificate for mimecast.com is issued by a third-party CA.
Signature algorithm: rsa-sha256
The certificate for mimecast.com uses an acceptable signature algorithm.
RSA key: 2048 bits
The certificate for mimecast.com uses an adequate RSA key of 2048 bits.
SCTs present in certificate
The certificate for mimecast.com contains Signed Certificate Timestamps.
No weak ciphers detected
No known weak cipher suites detected on mimecast.com.
Domain valid for 2410 days
Domain mimecast.com expires on 2032-12-13.
Domain transfer and delete locks enabled
Domain mimecast.com has clientTransferProhibited and clientDeleteProhibited locks.
TLD has good reputation
The .com TLD is not on known abuse watchlists.
DMARC reporting destinations look legitimate
DMARC rua/ruf addresses do not point to known URL shortener services.
MX records point to stable infrastructure
No MX records point to known dynamic DNS service domains.
Strong TLS configuration on primary MX
Primary MX (service-alpha-inbound-a.mimecast.com) uses TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 including Forward Secrecy.
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.
WHOIS registration data
Registrar: MarkMonitor Inc. | Created: 2003-02-20 | Expires: 2032-12-13 | Updated: 2024-11-12
WHOIS privacy protection not detected
Domain mimecast.com does not appear to have WHOIS privacy protection. Registrant details may be publicly visible.
Typosquat detected: mimcast.com (has MX!), mimecat.com (has MX!), minecast.com (has MX!), mikecast.com (has MX!), imecast.com
9 registered lookalike domain(s) that could be used for phishing against your brand. Showing top 5 of 9. Domains with MX records can send and receive email, making them high-risk phishing vectors.
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: service-alpha-inbound-a.mimecast.com
PTR record proves mail server legitimacy
MX: service-alpha-inbound-a.mimecast.com
Mail server at 91.220.42.231
→
PTR Record
Reverse DNS: service-alpha-inbound-a.mimecast.com
Mail Server Identity: service-alpha-inbound-b.mimecast.com
PTR record proves mail server legitimacy
MX: service-alpha-inbound-b.mimecast.com
Mail server at 91.220.42.231
→
PTR Record
Reverse DNS: service-alpha-inbound-a.mimecast.com
Mail Server Reputation: service-alpha-inbound-a.mimecast.com
RBL check ensures server is not blacklisted
MX: service-alpha-inbound-a.mimecast.com
Mail server at 91.220.42.231
→
RBL Status
Not blacklisted
Mail Server Reputation: service-alpha-inbound-b.mimecast.com
RBL check ensures server is not blacklisted
MX: service-alpha-inbound-b.mimecast.com
Mail server at 91.220.42.231
→
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: testing
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/mimecast.com.svg" alt="Email Security Grade">
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