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Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns2-42.azure-dns.net: "Knot DNS 3.1.2.1770717641.d6b376aff"; ns4-42.azure-dns.info: "Knot DNS 3.1.2.1770717641.d6b376aff". Hide or replace the version string.

SOA · The nameservers serve different versions of the zone: 12 on ns1-42.azure-dns.com (150.171.10.42), ns2-42.azure-dns.net (150.171.16.42), ns3-42.azure-dns.org (13.107.222.42), ns4-42.azure-dns.info (13.107.206.42); 1653609948 on dns1.p09.nsone.net (198.51.44.9), dns1.p09.nsone.net (2620:4d:4000:6259:7:9:0:1), dns2.p09.nsone.net (198.51.45.9), dns2.p09.nsone.net (2a00:edc0:6259:7:9::2), dns3.p09.nsone.net (198.51.44.73), dns3.p09.nsone.net (2620:4d:4000:6259:7:9:0:3), dns4.p09.nsone.net (198.51.45.73), dns4.p09.nsone.net (2a00:edc0:6259:7:9::4). This is normal for a few minutes after a change; if it lasts, zone transfers to the secondaries are failing.

SOA · negative caching TTL (minimum) 1m is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 1h, retry 10m, expire 7d, negative TTL 1m.

DNSSEC · The zone is not signed with DNSSEC, so answers can be spoofed. Enable DNSSEC at your DNS provider and publish the DS record at your registrar.

DNSSEC · DNSSEC is not enabled for this domain. Consider enabling DNSSEC to protect against DNS spoofing attacks.

MX · The following MX hosts could not be resolved to IPv6 addresses: mail.linkedin.com

MX · Found 6 MX records, which is more than the recommended maximum of 5. Too many MX records may indicate a misconfiguration.

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: google (1024 bits). Rotate to a 2048-bit key.

TLS · MTA-STS is not configured, so other mail servers fall back to unencrypted delivery when TLS fails or is stripped by an attacker. Publish a _mta-sts TXT record and a policy at https://mta-sts.<domain>/.well-known/mta-sts.txt.