clickup.com

Name: clickup.com Email Security Posture Assessment
Creator: RacterMX
License: https://creativecommons.org/licenses/by-nc/4.0/

Posture Score: 74/100

Scanned May 29, 2026 at 5:05 AM UTC

Identity

Attack Surface

Reputation

Identity Findings

Open recursion on nameserver: ns-769.awsdns-32.net

The nameserver ns-769.awsdns-32.net allows recursive queries from external sources, making it vulnerable to DNS amplification attacks.

💡 Disable recursion on ns-769.awsdns-32.net or restrict it to trusted networks only.

critical

SPF exceeds 10-lookup limit (13 lookups)

RFC 7208 limits SPF to 10 DNS lookups. Exceeding this causes PermError and SPF failures.

💡 Flatten your SPF record by replacing includes with direct ip4/ip6 mechanisms.

high

Weak DKIM RSA key (~1296 bits) for selector 'smtpapi'

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.

high

No DMARC aggregate report URI (rua=)

Without rua=, you will not receive aggregate reports about authentication results.

💡 Add rua=mailto:dmarc-reports@clickup.com to your DMARC record.

medium

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.clickup.com/.well-known/mta-sts.txt

medium

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.

medium

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@clickup.com").

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 DMARC record: 60s

The DMARC record has a TTL of 60s or less (below 300s).

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

low

SPF record length OK (189 bytes)

SPF record is within safe DNS packet size limits.

pass

DKIM cryptographic configuration is compliant

No RFC 8301 compliance issues detected in DKIM key configuration.

pass

DKIM key strength indicates modern key management

All DKIM keys use RSA-2048+ or Ed25519, consistent with current best practices.

pass

No external DMARC report destinations

All DMARC report URIs point to the same domain — no external authorization needed.

pass

Subdomains protected (sp=reject)

DMARC subdomain policy enforces quarantine or reject on unauthenticated subdomain mail.

pass

BIMI record is valid

BIMI is properly configured with a valid logo and DMARC enforcement.

pass

VMC URL is accessible

The BIMI VMC authority URL is reachable and returns a valid response.

pass

ARC support likely available

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

pass

Meets bulk sender authentication requirements

Domain has SPF, DKIM, and DMARC — meeting Google/Yahoo 2024 bulk sender requirements for email authentication.

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

IPv6 readiness is good

IPv6 records are present and properly configured.

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

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

The DMARC record contains tags deprecated in DMARCbis: pct. 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: alt3.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: 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

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.

informational

No DANE/TLSA records found

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

informational

Open mail ports on aspmx.l.google.com

Detected open mail-related ports: 25

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 5 different /16 networks, providing good diversity.

informational

SOA record parameters

Serial: 1, Refresh: 7200s, Retry: 900s, Expire: 1209600s, Min TTL: 86400s

informational

Authorized certificate authorities

CAA records restrict certificate issuance to: sectigo.com, pki.goog, amazon.com, digicert.com, letsencrypt.org

informational

Attack Surface Findings

Microsoft Autodiscover accessible without authentication

The Autodiscover endpoint at https://autodiscover.clickup.com/autodiscover/autodiscover.xml returns configuration data without requiring authentication. This exposes email server details to unauthenticated users.

💡 Configure the Autodiscover endpoint to require authentication before returning configuration data.

high

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

Domain enumerability: low

The domain has low enumerability. Proper NSEC3 configuration and limited CT exposure reduce the attack surface.

low

All MX records resolve correctly

No dangling MX records detected — all MX hostnames resolve to valid IP addresses.

pass

Explicit MX records present

The domain has explicit MX records — no implicit A-record fallback delivery.

pass

No internal information leakage detected

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

pass

No excessive DNS information exposure detected

No HINFO, LOC, RP records, version disclosures, or zone walking vulnerabilities were found.

pass

8 subdomain(s) discovered for clickup.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 clickup.com and its subdomains. Each certificate reveals subdomain names.

informational

Wildcard DNS record detected

A wildcard DNS record exists for *.clickup.com, resolving to 54.230.114.40, 54.230.114.19, 54.230.114.124, 54.230.114.83. Wildcard records make subdomain brute-forcing less effective but may mask misconfigurations.

informational

Mozilla Autoconfig endpoint detected

The Autoconfig endpoint at autoconfig.clickup.com is publicly accessible.

informational

Reputation Findings

Domain expires in 37 days

Domain clickup.com expires on 2026-07-05 (37 days).

💡 Renew the domain registration soon — it expires within 60 days. Enable auto-renewal if available.

high

Missing domain locks: clientDeleteProhibited

Domain clickup.com is missing protective locks: clientDeleteProhibited.

💡 Enable clientTransferProhibited and clientDeleteProhibited locks through your registrar to prevent unauthorized transfers or deletions.

high

HSTS enabled but missing preload directive on clickup.com

Strict-Transport-Security: max-age=31536000; includeSubDomains

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

low

HSTS enabled but missing preload directive on webmail.clickup.com

Strict-Transport-Security: max-age=31536000; includeSubDomains

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

low

Not listed on any DNS blacklists

Domain and MX IPs checked against 55 DNSBLs — no listings found.

pass

security.txt present

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

pass

TLS certificate valid for 160 days

Certificate for clickup.com expires on 2026-11-05.

pass

Certificate issued by Amazon RSA 2048 M04

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

pass

Signature algorithm: rsa-sha256

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

pass

RSA key: 2048 bits

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

pass

SCTs present in certificate

The certificate for clickup.com contains Signed Certificate Timestamps.

pass

No weak ciphers detected

No known weak cipher suites detected on clickup.com.

pass

No disposable email provider MX records

MX records for clickup.com do not match known disposable email provider patterns.

pass

Domain is 9093 days old

Domain clickup.com was registered 2001-07-05.

pass

No wildcard MX records

No wildcard MX records detected for clickup.com.

pass

TLD has good reputation

The .com TLD is not on known abuse watchlists.

pass

DMARC reporting destinations look legitimate

DMARC rua/ruf addresses do not point to known URL shortener services.

pass

MX records point to stable infrastructure

No MX records point to known dynamic DNS service domains.

pass

Strong TLS configuration on primary MX

Primary MX (aspmx.l.google.com) uses TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 including Forward Secrecy.

pass

SMTP banner from hosted mail provider

The MX (aspmx.l.google.com) is a hosted mail service. Banner alignment is managed by the provider and not actionable by the domain owner.

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 contacts found for MX IPs

Abuse contact information retrieved via abusix.org DNS lookup.

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

WHOIS registration data

Registrar: Amazon Registrar, Inc. | Created: 2001-07-05 | Expires: 2026-07-05 | Updated: 2026-05-13

informational

WHOIS privacy protection enabled

Domain clickup.com has WHOIS privacy/redaction enabled.

informational

Bulletproof Hosting Detection — API key required

Checking IPs against known bulletproof hosting providers requires a threat intelligence API key.

informational

Threat Intelligence Feeds — API key required

Checking domain against threat intelligence feeds requires API keys (e.g., VirusTotal, AbuseIPDB).

informational

Typosquat detected: lickup.com (has MX!), cickup.com (has MX!), clicku.com (has MX!), clcikup.com (has MX!), clickpu.com (has MX!)

13 registered lookalike domain(s) that could be used for phishing against your brand. Showing top 5 of 13. Domains with MX records can send and receive email, making them high-risk phishing vectors.

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: aspmx.l.google.com

PTR record proves mail server legitimacy

MX: aspmx.l.google.com Mail server at 74.125.193.27 → PTR Record Reverse DNS: ig-in-f27.1e100.net

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

PTR record proves mail server legitimacy

MX: alt3.aspmx.l.google.com Mail server at 192.178.213.27 → PTR Record Reverse DNS: yugrqzs-in-f27.1e100.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: alt1.aspmx.l.google.com

PTR record proves mail server legitimacy

MX: alt1.aspmx.l.google.com Mail server at 173.194.76.27 → PTR Record Reverse DNS: ws-in-f27.1e100.net

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

PTR record proves mail server legitimacy

MX: alt2.aspmx.l.google.com Mail server at 142.250.102.27 → PTR Record Reverse DNS: rb-in-f27.1e100.net

Mail Server Reputation: aspmx.l.google.com