hochschule-ruhr-west.de

Delegation · all IPv4 addresses are in 193.174.75.0/24; all IPv6 addresses are in 2001:638:d::/48. A single network failure takes all nameservers down; RFC 2182 recommends topologically separate networks (anycast setups are an exception).

DNSSEC · The earliest signature expires at 2026-10-27 05:10 UTC (in 126h0m0s). Check that automatic re-signing works.

DNSSEC · NSEC3 uses 10 iterations and a 14-byte salt. RFC 9276 recommends 0 iterations and no salt: extra iterations cost resolvers CPU and add no real protection, and some validators treat high counts as insecure.

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: mx0.hs-rw.de, mx1.hs-rw.de, mx2.hs-rw.de

DNSSEC · DNSKEY signatures expire at 2026-10-27T05:10:49Z (in 126h0m0s). Check that re-signing works.

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:...".