semafor.com

SOA · expire 3d is shorter than 7d; secondaries stop answering too soon when the primary is down. Current values: refresh 6h, retry 1h, expire 3d, negative TTL 5m.

DNSSEC · The zone is signed but the parent has no DS record, so the signatures are not used. Publish the DS record at your registrar.

DNSSEC · NSEC3 uses 1 iteration and a 8-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.

Records · These records have a TTL below 5m, causing extra queries and slower lookups: A (1m), MX (1m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 2d and in the zone 6h; resolvers may use either.

DNSSEC · The zone is signed (DNSKEY present) but the parent has no DS record, so the chain of trust is incomplete. Publish the DS record at your registrar.

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