← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope Not all SPF mechanisms consume DNS lookups. Understanding which mechanisms count is essential for optimising SPF records: SPF flattening is the process of replacing include: […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope v=spf1 — version identifier; always the first element. Required.: v=spf1 — version identifier; always the first element. Required. Common lookup-intensive SPF includes and their approximate […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope SPF failure means the sending IP is not authorised in the SPF record for the MAIL FROM domain. The Authentication-Results header will show spf=fail or […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope This split ownership creates a coordination problem. When a company changes its email sending domain: Understanding the PTR validation chain requires understanding how Gmail (and […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope The most frequently encountered authentication failure patterns in email headers, with their diagnostic indicators and root causes: ISPs add proprietary X-headers that reveal their internal […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope Implementation steps with Cloudflare DNS (which automates most of DNSSEC setup): The DS record submission step — connecting the domain’s DNSSEC chain to the parent […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope Email authentication relies on DNS records that, without DNSSEC, can be targeted by DNS cache poisoning attacks. The specific protection DNSSEC provides for each authentication […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope The tool that is right for you depends on what you actually need, which requires being honest about your situation rather than buying the demo […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope RUA (aggregate) and RUF (forensic) reports serve different diagnostic purposes. Understanding when to rely on each prevents confusion when troubleshooting authentication failures.: RUA (aggregate) and […]
← Back to Email Authentication Knowledge Base ⚡ Production Engineering Runbook • Updated for 2026 ISP Mandates • 15 min read Executive Engineering Runbook Technical Overview & Production Verification Scope Verify before publishing your first DMARC record: Collect reports for at least 2–4 weeks before making any policy decisions. For complex organisations with many sending […]