DMARC: Settings & Switches
Plain-English guide to DMARC tags — p, adkim/aspf, rua/ruf, fo, pct — with a staged rollout from none → quarantine → reject and copy-paste policy examples.
Tutorials
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DKIM Alignment Explained
What DKIM alignment is, how relaxed (adkim=r) vs strict (adkim=s) affect pass/fail, and how to align d= with your From domain for DMARC success.
Microsoft DSN / Bounce Codes – Complete Glossary (with Fixes)
A practical, searchable glossary of Microsoft (Outlook/Hotmail/Office 365) DSN / SMTP error codes with plain‑English causes and step‑by‑step remedies.
Gmail Deliverability Playbook — Diagnose, Fix, Prevent
Practical guide to improve Gmail delivery and inboxing: Postmaster reputation rehab, authentication alignment, 2024+ bulk‑sender requirements, and triage for common Gmail deferrals.
Deliverability: Fixing Outlook & Gmail
Step-by-step to get mail landing in Outlook and Gmail: SPF, DKIM, DMARC alignment, reputation checks, and common blocklist pitfalls.