dvgw.de

Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns4-06.azure-dns.info: "Knot DNS 3.1.2.1770717641.d6b376aff". Hide or replace the version string.

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

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

DMARC · DMARC record has no rua tag, so you receive no aggregate reports about who sends mail as your domain. Add rua=mailto:...

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: selector1 (1024 bits). Rotate to a 2048-bit key.

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:...".