bpb.de

Delegation · The addresses at the parent (glue) differ from the addresses in the zone: ns3.teamware-gmbh.de (glue 217.19.160.3, 2a03:ad00:0:4::f3, zone 217.19.160.3). Update the glue at your registrar.

Delegation · None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.

Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns.teamware-gmbh.de: "9.18.39-0ubuntu0.24.04.7-Ubuntu"; ns3.teamware-gmbh.de: "9.18.39-0ubuntu0.24.04.7-Ubuntu". 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 · The following MX hosts could not be resolved to IPv6 addresses: mx1.bund.de, mx2.bund.de

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

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:...".