Email deliverability as an engineering problem

Email deliverability as an engineering problem
Not copywriting. Plumbing. These treat inbox placement like infra.

— 1. DMARC, DKIM, SPF in one diagram — the alignment rules that actually decide gmail placement, drawn clearly. Source: dmarcian.
— 2. Google and Yahoo's 2024 bulk-sender rules — the one-click unsubscribe header spec and spam-rate threshold. Source: Google Postmaster docs.
— 3. IP warming schedules that work — day-by-day volume ramps from a real ESP migration. Source: Postmark blog.
— 4. Seed-list testing vs Google Postmaster Tools — why both, and what each blind-spots. Source: Word to the Wise.

Skip if you send under 5k a day. Essential the week before any domain or ESP migration.

That's the stack for this week. Forward to a teammate.