Sender Best Practices

What we recorded

Read 2026-11-11 through a fetch tool that can summarise. Undated (footer 2026); enforcement from February 2024. All senders: SPF or DKIM at a minimum. Bulk senders: both SPF and DKIM, a valid DMARC policy of at least p=none that passes, From-domain aligned with SPF or DKIM, a list-unsubscribe header supporting one-click unsubscribe, honour unsubscribes within 2 days, keep spam rate below 0.3% (computed on mail delivered to the inbox). The page gives no volume threshold for who counts as a bulk sender.

Claims that cite it

• Yahoo requires all senders to use SPF or DKIM, and bulk senders to use both, publish a DMARC policy of at least p=none that passes, support one-click unsubscribe, honour unsubscribes within 2 days and keep the spam rate below 0.3%. It does not say what volume makes a sender bulk. (strong)