SPF, DKIM, and DMARC are DNS records that let mail servers verify your domain's legitimacy as a sender.
Implementation Order
- Configure SPF and DKIM
- DMARC with p=none (collect reports)
- After 2–4 weeks — p=quarantine
- After 1–3 months — p=reject
⚠️ Don't set p=reject immediately — collect reports for a month first.