uswitch.com

SOA · expire 55h16m43s is shorter than 7d; secondaries stop answering too soon when the primary is down; negative caching TTL (minimum) 105h40m54s is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 7h53m49s, retry 3h56m54s, expire 55h16m43s, negative TTL 105h40m54s.

DNSSEC · The zone is not signed with DNSSEC, so answers can be spoofed. Enable DNSSEC at your DNS provider and publish the DS record at your registrar.

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

DNSSEC · DNSSEC is not enabled for this domain. Consider enabling DNSSEC to protect against DNS spoofing attacks.

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.