#email

E-mail deliverability in 2026: SPF, DKIM, DMARC and the inbox you earn

Google and Yahoo stopped tolerating what they used to wave through, Microsoft followed, and the bar is now the floor rather than the ceiling. The authentication triad explained by people who run the mail servers — plus the alignment trap, a p=reject rollout that doesn't blackhole your invoices, warmup schedules, and the metrics that warn you weeks before delivery dies.