investors.com

Delegation · The addresses at the parent (glue) differ from the addresses in the zone: cf1.investors.com (glue 162.159.0.39, zone 162.159.0.39, 2400:cb00:2049:1::a29f:27); cf2.investors.com (glue 162.159.1.39, zone 162.159.1.39, 2400:cb00:2049:1::a29f:127). Update the glue at your registrar.

Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: cf1.investors.com: "2026.10.2"; cf2.investors.com: "2026.10.2". Hide or replace the version string.

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.

Records · These records have a TTL below 5m, causing extra queries and slower lookups: MX (1m). 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.

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: mxa-00596a01.gslb.pphosted.com, mxb-00596a01.gslb.pphosted.com

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: google (1024 bits), s1 (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.