The Google/Yahoo sender requirements, as a working checklist
Gmail and Yahoo have required these from senders since February 2024, and starting November 2025 Gmail rejects more of the mail that fails them instead of only filtering it. This is the checklist we run domains through, in the order things actually break.
The checklist
1. SPF publishes and passes: one record, under 10 lookups, ending ~all or -all. 2. DKIM signs: 2048-bit key, every sending service enabled. 3. DMARC exists: p=none minimum with a rua= address you actually read. 4. Alignment: the From domain matches the SPF or DKIM domain — the step newsletter tools most often miss; use a custom sending domain, never the tool's shared one. 5. One-click unsubscribe (RFC 8058 List-Unsubscribe-Post headers) on marketing mail, honored within 2 days. 6. Spam rate below 0.1%, never above 0.3% — register in Google Postmaster Tools, it is free and it is where Google tells you what it thinks of you. 7. Valid forward and reverse DNS on sending IPs (your ESP's job; ask them to confirm it). 8. TLS on delivery.
The failure mode that surprises people
Compliance is per-stream but reputation is per-domain: a forgotten survey tool sending unaligned mail as your domain drags down the reputation your invoice mail depends on. This is why monitoring DMARC reports matters even at p=none — the reports are the only place you see every stream claiming your name, including the ones marketing signed up for without telling IT.
Run the free MonitorBase check for an instant pass/fail on points 1–3. Alignment (point 4) and the rest only show up in the DMARC reports, so keep an eye on those. Five seconds now beats a Tuesday of "why do all our quotes bounce?".
Free tools that help
- DMARC Inspector: Parse and grade your DMARC policy, reporting addresses and alignment settings.
- SPF Surveyor: Visualize the full SPF include tree and count DNS lookups against the limit of 10.