mAIb Deliverability Repair

Yahoo sender requirements

Yahoo’s requirements closely track Google’s, with one-click unsubscribe and a two-day honouring window given particular emphasis.

Free. No signup. A full scan runs every check, not just this one.

What Yahoo requires

  • SPF and DKIM authentication, aligned with the visible From domain.
  • A DMARC record, at least p=none.
  • Valid reverse DNS on sending IPs, and TLS on delivery.
  • Spam complaint rates kept below 0.3%.
  • One-click unsubscribe per RFC 8058 for bulk mail, with unsubscribe requests honoured within two days.

One-click unsubscribe, specifically

RFC 8058 needs two headers working together: List-Unsubscribe carrying an HTTPS URL, and List-Unsubscribe-Post: List-Unsubscribe=One-Click. A message with only the first does not qualify, and that is the most common way senders get this wrong — the header has existed for years, and the -Post half is the new part.

The two-day honouring window is a process requirement rather than a technical one. No scanner can verify it; it is worth stating because it is a real obligation that carries real consequences.

What a domain scan shows

SPF, DKIM key publication, and the DMARC record and policy. Alignment, unsubscribe headers, reverse DNS and complaint rate are all properties of your sending rather than your domain, and are reported as not determined here until a message is supplied.

Source: Yahoo's published sender best practices, retrieved 2026-09-14.

Find, explain, repair, verify

The scan is free and complete. If it finds something wrong, the £19 Repair Pack gives you the exact records to publish for your domain and your providers, the order to publish them in, and the previous values so you can undo anything.

Scan your domain

Ruleset 2026.09.14, sources verified 2026-09-14. Methodology.