DNS & Email Security Report for spamhaus.org

• A record presentcritical

  1 A record(s) found

• AAAA record presentrecommended

  1 AAAA record(s) found

• MX records presentrecommended

  2 MX record(s) found

• NS records presentcritical

  6 NS record(s) found

• SOA record presentcritical

  SOA record found

• Multiple nameserversrecommended

  6 nameservers configured ✓

• SOA serial formatinfo

  Serial 2026040102 (YYYYMMDDnn format)

• SOA timers validinfo

  Refresh: 3600s ✓, Retry: 600s ✓, Expire: 2419200s ✓

• No lame nameserversinfo

  6 NS all responding ✓

• Glue records presentinfo

  4 glue record(s)

• WWW record configuredinfo

  CNAME: www.spamhaus.org.cdn.cloudflare.net

• MX servers have PTR recordsinfo

  1/2 MX IPs have PTR. Configure reverse DNS for your mail servers

• MX servers have FCrDNSinfo

  1/2 MX IPs have FCrDNS. PTR hostnames must resolve back to the original IP.

• DNSSEC signedrecommended

  DNSSEC not configured. Enable DNSSEC at your domain registrar to protect against DNS spoofing

• DNSSEC validation OKcritical

  Not applicable (DNSSEC not enabled)

• NSEC3 RFC 9276 compliantrecommended

  Not applicable (domain uses NSEC or is not DNSSEC-signed)

• RRSIG signatures validrecommended

  Not applicable (DNSSEC not enabled)

• Modern DNSSEC algorithmoptional

  Not applicable (DNSSEC not enabled)

• DS digest algorithm modernrecommended

  Not applicable (no DS records or DNSSEC not enabled)

• DNSKEY algorithm secureoptional

  Not applicable (DNSSEC not enabled)

• RRSIG TTL saferecommended

  Not applicable (DNSSEC not enabled or no RRSIG data)

• Chain of trust completecritical

  DNSSEC not enabled

• Website reachable via IPv6recommended

  1 AAAA record(s) ✓

• Mail servers reachable via IPv6recommended

  0/2 MX servers have IPv6. Add AAAA records for your mail servers

• Nameservers reachable via IPv6recommended

  6/6 NS server(s) with IPv6 ✓

• SPF record presentcritical

  v=spf1 a:mail-out.spamhaus.org a:mail-out1.spamhaus.org a:mail-out2.spamhaus.org ~all

• SPF syntax validcritical

  SPF syntax is correct ✓

• SPF policy strict (-all)recommended

  SPF uses ~all or ?all. Change to -all for strict enforcement

• DKIM foundrecommended

  No DKIM found. Configure DKIM signing with your email provider

• DMARC record presentrecommended

  v=DMARC1; p=reject; pct=100; fo=1; ri=3600; rua=mailto:[email protected],mailto:[email protected]; ruf=mailto:[email protected]

• DMARC policy quarantine or betterrecommended

  DMARC policy: reject ✓

• DMARC policy rejectoptional

  DMARC policy: reject ✓

• BIMI record presentoptional

  No BIMI record. Add TXT at default._bimi with logo URL (requires DMARC p=quarantine+)

• BIMI configuration validoptional

  No BIMI configured

• MTA-STS record presentoptional

  No MTA-STS. Add TXT at _mta-sts and host policy at /.well-known/mta-sts.txt

• MTA-STS policy enforcedoptional

  MTA-STS not configured

• MX records validcritical

  2 MX record(s) ✓

• MX domains use DNSSECrecommended

  0/1 MX domain(s) have DNSSEC. Ask your mail provider to enable DNSSEC

• MX DNSSEC validation OKrecommended

  DNSSEC not enabled for MX domains

• Mail servers not blacklistedcritical

  1/1 MX server(s) blacklisted: mx.spamhaus.org on UCEPROTECT L3

• No critical blacklist listingscritical

  No critical listings, but some servers are on blacklists

• CAA records presentrecommended

  No CAA records. Add CAA record to specify allowed certificate authorities

• CAA policy strictoptional

  CAA not strict. Add CAA 0 issue "letsencrypt.org" (or your CA) to restrict issuance

• TLSA records (DANE)optional

  No TLSA/DANE records. Add TLSA at _25._tcp.mail for DANE email encryption

• DANE configuration validoptional

  No DANE configured

• No sensitive info in TXTcritical

  No sensitive data leaked ✓

• Verification records reviewedinfo

  3 verification record(s): Google, Slack, Zoom. Consider if all are still needed

• HTTPS availablecritical

  HTTPS working (status 200) ✓

• Valid certificatecritical

  Certificate chain is valid and trusted ✓

• HTTP redirects to HTTPScritical

  HTTP automatically redirects to HTTPS ✓

• HSTS enabledrecommended

  HSTS enabled (max-age=300, includeSubDomains, preload) ✓

• HSTS max-age >= 1 yearoptional

  max-age=300 is too short. Set to 31536000 (1 year) or higher

• X-Frame-Options headerrecommended

  X-Frame-Options: SAMEORIGIN ✓

• X-Content-Type-Options headerrecommended

  X-Content-Type-Options: nosniff ✓

• Content-Security-Policy headerrecommended

  Content-Security-Policy configured ✓

• Referrer-Policy headerrecommended

  Referrer-Policy: strict-origin ✓

• security.txt presentoptional

  security.txt found

• security.txt validoptional

  security.txt missing required fields. Must have Contact: and Expires: per RFC 9116

• HTTP/3 (QUIC) supportedoptional

  HTTP/3 (QUIC v1) on port 443 Detection methods: QUIC probe: inconclusive (no reply — trigger may be dropped or UDP/443 filtered) Alt-Svc header: h3=":443" Cache: 24h (ma=86400)

• QUIC UDP reachableinfo

  QUIC probe inconclusive (no reply — trigger may be dropped or UDP/443 filtered). Not a negative signal; h3 is judged from Alt-Svc / HTTPS record

• HTTPS DNS record (SVCB)optional

  No HTTPS DNS record (type 65). Add HTTPS record for faster HTTP/3 discovery: spamhaus.org IN HTTPS 1 . alpn="h3,h2"

Implement DNSSEC

Activate DNSSEC with your domain registrar and add the DS records to your parent zone. This protects against DNS spoofing attacks.

Impact: Significantly increases security and prevents DNS manipulation

Implement DKIM

Configure DKIM signing with your email provider and publish the DKIM public key in DNS.

Impact: Improves email deliverability and prevents spoofing

Configure reverse DNS for mail servers

Ask the owner of each mail server IP address to set a PTR record, for example 203.0.113.10 -> mail.yourdomain.com.

Impact: Improves mail-server trust signals and reduces deliverability risk

Add CAA records

Define which Certificate Authorities may issue SSL certificates, for example: "0 issue letsencrypt.org"

Impact: Prevents unauthorized certificate issuance

IPv6 for mail servers

Add AAAA records for your MX servers to support email via IPv6.

Impact: Improves email reachability for IPv6 networks