mdc-berlin.de

Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns1.mdc-berlin.eu: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:11:18 by root@413bd54b27a2)"; ns3.mdc-berlin.eu: "PowerDNS Authoritative Server 4.9.11 (built Oct 15 2025 10:16:24 by root@localhost)". 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.

DKIM · The _domainkey name exists but no DKIM key was found under the common selectors. Selectors are provider-specific; check yours with -selector.

MX · The following MX hosts could not be resolved to IPv6 addresses: a2061.mx.srv.dfn.de, b2061.mx.srv.dfn.de, c2061.mx.srv.dfn.de

DMARC · DMARC policy only applies to 25% of failing mail (pct=25). Raise pct to 100 once you are confident in your setup.

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:...".