mollie.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 · 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.

DMARC · DMARC policy is set to 'quarantine'. Consider upgrading to 'reject' for stronger protection once you've verified legitimate emails are passing authentication.

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.