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Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: doug.ns.cloudflare.com: "2026.10.2"; harmony.ns.cloudflare.com: "2026.10.2". Hide or replace the version string.

Records · These records have a TTL below 5m, causing extra queries and slower lookups: A (1m39s), MX (2m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 2d and in the zone 1d; resolvers may use either.

MX · The following MX hosts could not be resolved to IPv6 addresses: de-smtp-inbound-1.mimecast.com, de-smtp-inbound-2.mimecast.com

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: google (1024 bits), s2 (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.