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vultr.com

Name: vultr.com Email Security Posture Assessment
Creator: RacterMX

Posture Score: 82/100

Scanned May 8, 2026 at 8:05 AM UTC

Identity

Attack Surface

Reputation

Identity Findings

Open recursion on nameserver: ns1.choopadns.com

The nameserver ns1.choopadns.com allows recursive queries from external sources, making it vulnerable to DNS amplification attacks.

💡 Disable recursion on ns1.choopadns.com or restrict it to trusted networks only.

critical

Open recursion on nameserver: ns2.choopadns.com

The nameserver ns2.choopadns.com allows recursive queries from external sources, making it vulnerable to DNS amplification attacks.

💡 Disable recursion on ns2.choopadns.com or restrict it to trusted networks only.

critical

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.

low

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@vultr.com").

low

SPF has ip4 mechanisms but no ip6

The SPF record authorizes IPv4 addresses but not IPv6. Your MX servers have AAAA records, so IPv6 mail delivery is possible without SPF authorization.

💡 Add ip6: mechanisms to the SPF record for your IPv6 mail server addresses.

low

Shared IP 170.10.150.242 used by multiple MX servers

The IP 170.10.150.242 is shared across 2 MX hostnames, reducing redundancy.

💡 Use unique IP addresses for each MX server for better redundancy.

low

Shared IP 170.10.152.242 used by multiple MX servers

The IP 170.10.152.242 is shared across 2 MX hostnames, reducing redundancy.

💡 Use unique IP addresses for each MX server for better redundancy.

low

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"

low

Very low TTL on MX records: 272s

7 MX records have a TTL of 272s or less (below 300s).

💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.

low

Very low TTL on TXT records: 272s

23 TXT records have a TTL of 272s or less (below 300s).

💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.

low

Very low TTL on SPF record: 272s

The SPF record has a TTL of 272s or less (below 300s).

💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.

low

Very low TTL on DMARC record: 272s

The DMARC record has a TTL of 272s or less (below 300s).

💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.

low

NS TTL mismatch between parent and authoritative zone

The NS record TTL in the parent zone (~7172s) differs significantly from the authoritative zone (~86400s).

💡 Align NS record TTLs between the parent zone delegation and the authoritative zone.

low

SPF record is valid

The SPF record is properly configured with valid syntax and within lookup limits.

pass

DKIM records are valid

DKIM records found and validated for selectors: google, s1, s2

pass

DKIM cryptographic configuration is compliant

No RFC 8301 compliance issues detected in DKIM key configuration.

pass

ARC support likely available

MX server software appears to support ARC headers for authentication preservation.

pass

SMTP security checks passed

No open relay, VRFY/EXPN, or banner disclosure issues detected.

pass

SMTP RFC 5321 compliance checks passed

The mail server accepts postmaster@ and abuse@ and uses a valid FQDN in EHLO.

pass

STARTTLS downgrade resistance is adequate

STARTTLS is supported with modern TLS and protected by MTA-STS and/or DANE.

pass

DNS responses are consistent across all nameservers

All authoritative nameservers return consistent answers with proper AA flags.

pass

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.

informational

DMARC alignment: adkim=r, aspf=r

DKIM alignment is relaxed, SPF alignment is relaxed.

informational

DMARC failure reporting: fo=1

Failure reports generated when any authentication mechanism fails.

informational

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.

informational

Deprecated DMARCbis tags found: pct, ri

The DMARC record contains tags deprecated in DMARCbis: pct, ri. Consider removing these for forward compatibility.

informational

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.

informational

Shared/free email hosting detected: aspmx.l.google.com

The MX record points to a known shared or free email hosting provider.

informational

Shared/free email hosting detected: alt4.aspmx.l.google.com

The MX record points to a known shared or free email hosting provider.

informational

Shared/free email hosting detected: alt3.aspmx.l.google.com

The MX record points to a known shared or free email hosting provider.

informational

Shared/free email hosting detected: alt1.aspmx.l.google.com

The MX record points to a known shared or free email hosting provider.

informational

Shared/free email hosting detected: alt2.aspmx.l.google.com

The MX record points to a known shared or free email hosting provider.

informational

No DANE/TLSA records found

DANE is not configured for any MX server. This is optional but provides strong certificate binding.

informational

No BIMI record found

BIMI is not configured. Your brand logo will not display in supporting email clients.

informational

Open mail ports on usb-smtp-inbound-1.mimecast.com

Detected open mail-related ports: 25, 587

informational

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.

informational

MX IP network diversity

MX IPs span 6 different /16 networks, providing good diversity.

informational

SOA record parameters

Serial: 0, Refresh: 10800s, Retry: 3600s, Expire: 604800s, Min TTL: 3600s

informational

Authorized certificate authorities

CAA records restrict certificate issuance to: digicert.com, globalsign.com, comodoca.com

informational

Attack Surface Findings

DNS ANY query returns 39 record(s)

The DNS server responds to ANY queries with 39 record(s), creating significant DNS amplification risk.

💡 Configure the DNS server to refuse or minimize ANY query responses per RFC 8482.

medium

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.

medium

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.

medium

No internal information leakage detected

No non-routable IP addresses or internal references were found in public DNS records.

pass

No email autodiscovery endpoints detected

No Microsoft Autodiscover, Mozilla Autoconfig, or email SRV records were found.

pass

10 subdomain(s) discovered for vultr.com

Subdomains were enumerated via Certificate Transparency logs, DNS wordlist brute-forcing, and DNS record analysis.

informational

0 certificate(s) found in CT logs

Certificate Transparency logs contain 0 certificate(s) for vultr.com and its subdomains. Each certificate reveals subdomain names.

informational

Reputation Findings

HSTS enabled but missing preload directive on vultr.com

Strict-Transport-Security: max-age=63072000

💡 Add the "preload" directive to the HSTS header and submit the domain to hstspreload.org.

low

security.txt present

Found security.txt at https://vultr.com/.well-known/security.txt.

pass

TLS certificate valid for 190 days

Certificate for vultr.com expires on 2026-11-14.

pass

Certificate issued by Sectigo Public Server Authentication CA DV R36

The certificate for vultr.com is issued by a third-party CA.

pass

Signature algorithm: rsa-sha256

The certificate for vultr.com uses an acceptable signature algorithm.

pass

RSA key: 2048 bits

The certificate for vultr.com uses an adequate RSA key of 2048 bits.

pass

SCTs present in certificate

The certificate for vultr.com contains Signed Certificate Timestamps.

pass

No weak ciphers detected

No known weak cipher suites detected on vultr.com.

pass

Domain valid for 1977 days

Domain vultr.com expires on 2031-10-06.

pass

Domain transfer and delete locks enabled

Domain vultr.com has clientTransferProhibited and clientDeleteProhibited locks.

pass

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.

informational

Abuse contact lookup failed

Could not query abuse contact information.

informational

PhishTank — API key required

PhishTank phishing database check requires an API key.

informational

Sender Score — API key required

Sender Score reputation check requires an API key.

informational

Cisco Talos — API key required

Cisco Talos IP reputation check requires an API key.

informational

Could not connect to webmail.vultr.com

HTTPS request to https://webmail.vultr.com failed or timed out.

informational

WHOIS registration data

Registrar: GoDaddy.com, LLC | Created: 2008-10-06 | Expires: 2031-10-06 | Updated: 2024-04-11

informational

WHOIS privacy protection enabled

Domain vultr.com has WHOIS privacy/redaction enabled.

informational

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: usb-smtp-inbound-1.mimecast.com

PTR record proves mail server legitimacy

MX: usb-smtp-inbound-1.mimecast.com Mail server at 170.10.150.242 → PTR Record Reverse DNS: usb-smtp-delivery-2.mimecast.com

Mail Server Identity: usb-smtp-inbound-2.mimecast.com

PTR record proves mail server legitimacy

MX: usb-smtp-inbound-2.mimecast.com Mail server at 170.10.150.242 → PTR Record Reverse DNS: usb-smtp-delivery-2.mimecast.com

Mail Server Identity: aspmx.l.google.com

PTR record proves mail server legitimacy

MX: aspmx.l.google.com Mail server at 209.85.202.26 → PTR Record Reverse DNS: dg-in-f26.1e100.net

Mail Server Identity: alt4.aspmx.l.google.com

PTR record proves mail server legitimacy

MX: alt4.aspmx.l.google.com Mail server at 142.251.127.26 → PTR Record Reverse DNS: lcfrai-in-f26.1e100.net

Mail Server Identity: alt3.aspmx.l.google.com

PTR record proves mail server legitimacy

MX: alt3.aspmx.l.google.com Mail server at 192.178.213.26 → PTR Record Reverse DNS: yugrqzs-in-f26.1e100.net

Mail Server Identity: alt1.aspmx.l.google.com

PTR record proves mail server legitimacy

MX: alt1.aspmx.l.google.com Mail server at 173.194.76.26 → PTR Record Reverse DNS: ws-in-f26.1e100.net

Mail Server Identity: alt2.aspmx.l.google.com

PTR record proves mail server legitimacy

MX: alt2.aspmx.l.google.com Mail server at 142.250.102.26 → PTR Record Reverse DNS: rb-in-f26.1e100.net

Mail Server Reputation: usb-smtp-inbound-1.mimecast.com