The Ultimate Checklist for an A+ Email Spam Filter in 2026
Introduction Email threats keep evolving. This checklist walks you through practical, prioritized steps to build and maintain an A+ spam filter that protects deliverability, brand trust, and users in 2026.
1 — Authentication and DNS records (highest priority)
- SPF: Publish a single, accurate SPF record that lists all legitimate senders. Avoid exceeding 10 DNS lookups; use managed/dynamic SPF if needed.
- DKIM: Sign all outbound mail with DKIM. Use 2048-bit keys, rotate keys regularly, and ensure every sending service signs with aligned selectors.
- DMARC: Start with p=none to monitor, fix issues, then move to p=quarantine and finally p=reject. Publish rua/ruf reporting addresses and a reasonable pct during transitions.
- MTA-STS & TLS-RPT: Publish MTA-STS policy and enable TLS reporting to enforce and monitor encrypted transport.
- BIMI (optional for trust): After DMARC enforcement, add BIMI and obtain a VMC if your provider requires it.
2 — Inventory and source hygiene
- Complete
Leave a Reply