duo.nl

DNSSEC · NSEC3 uses 10 iterations and a 7-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.

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

DNSSEC · DNSKEY signatures expire at 2026-10-25T16:55:32Z (in 92h0m0s). Check that re-signing works.

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: selector1 (1024 bits), selector2 (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.

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:...".