Authentication & DNS Engineering
Operational documentation for designing, deploying, validating and monitoring email identity.
SPF Architecture and Scope
Design SPF around the actual return-path domains and outbound infrastructure rather than visible From addresses.
Production SPF Record Design
Build maintainable SPF records that stay within DNS lookup limits and preserve ownership boundaries.
SPF Include Chains and Lookup Limits
Understand recursive includes, redirects, void lookups, and failure modes.
DKIM Key Management
Generate, store, publish, rotate, and retire DKIM keys safely.
DKIM CNAME Delegation
Delegate selectors to a sending platform while preserving customer-domain alignment.
DKIM Selector Strategy
Choose selector naming and rotation patterns for customers, streams, and environments.
DMARC Foundation
Deploy DMARC with correct identifier alignment, reporting, and staged enforcement.
DMARC Rollout to Enforcement
Move from p=none to quarantine or reject using measured evidence.
DMARC Aggregate Reporting
Operate rua reporting, normalization, ownership, and exception workflows.
SPF and DKIM Alignment
Understand relaxed and strict alignment and how forwarding affects each path.
Return-Path and Bounce Domain Design
Separate visible identity, envelope identity, and bounce processing safely.
PTR, HELO and Forward DNS
Build consistent SMTP identity across PTR, A/AAAA, and EHLO names.
MX Record Design
Design inbound MX records, priorities, failover, and operational checks.
DNS Change Management
Plan TTL reductions, rollout windows, validation, and rollback.
DNSSEC Operations
Understand signing, delegation, rollover, and failure isolation.
SMTP TLS Reporting
Deploy TLS-RPT records and operationalize report handling.
MTA-STS Deployment
Publish policy, serve HTTPS policy files, and stage enforcement safely.
BIMI Readiness
Prepare brand assets, authentication, policy, and operational prerequisites.
Multi-Tenant Authentication Design
Separate customer selectors, return paths, tracking domains, and ownership.
Authentication Monitoring
Monitor DNS drift, signature failures, report changes, and selector expiry.
Provider-Specific Validation
Verify authentication results across Gmail, Microsoft, Yahoo, Apple, and enterprise gateways.
Authentication During Migration
Preserve alignment while moving IPs, MTAs, DNS providers, or sending platforms.
Authentication Incident Response
Contain and recover from broken SPF, DKIM, DMARC, PTR, or DNS changes.
Authentication Go-Live Checklist
Validate the complete identity chain before production traffic.