Executive's DNS Intelligence Brief

SPF (Sender Policy Framework) tells receiving mail servers which IP addresses are authorized to send email for your domain. Without SPF, any server can claim to send as your domain.

DMARC (Domain-based Message Authentication, Reporting & Conformance) tells receivers how to handle messages that fail SPF/DKIM checks. Without DMARC, failed authentication checks are ignored. Start with p=none and rua reporting to monitor, then escalate to p=quarantine and p=reject.

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to outgoing emails, proving they haven't been tampered with. Enable DKIM in your email provider's settings.

Publish CAA DNS records to restrict which Certificate Authorities can issue TLS certificates for your domain. Specify your preferred CA (e.g., letsencrypt.org, digicert.com).

Publish an MTA-STS DNS record and host a policy file at https://mta-sts.yourdomain.com/.well-known/mta-sts.txt. This tells senders to require TLS when delivering mail to your domain.

TLS-RPT (TLS Reporting) sends you reports about TLS connection failures when other servers try to deliver mail to your domain. Helps diagnose MTA-STS and STARTTLS issues.

DNSSEC (DNS Security Extensions) cryptographically signs DNS responses, preventing attackers from forging DNS answers. Contact your DNS hosting provider to enable DNSSEC signing.