nbb.be

Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns4-03.azure-dns.info: "Knot DNS 3.1.2.1770717641.d6b376aff". Hide or replace the version string.

DMARC · DMARC policy is set to 'quarantine'. Consider upgrading to 'reject' for stronger protection once you've verified legitimate emails are passing authentication.

MX · Only one MX record found. For better email reliability, consider adding at least one backup MX server.

DMARC · DMARC subdomain policy is sp=none, so spoofed mail from subdomains is not blocked. Consider sp=quarantine or sp=reject.

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: s2 (1024 bits). Rotate to a 2048-bit key.

TLS · With mode: testing, senders only report TLS problems (via TLS-RPT) and still deliver without TLS. Switch to mode: enforce once reports are clean. max_age is only 3600 seconds; use at least a week (604800) so the policy stays cached.

TLS · MTA-STS or DANE is used without TLS-RPT, so you get no reports when senders fail to deliver because of TLS problems. Publish _smtp._tls TXT "v=TLSRPTv1; rua=mailto:...".