What are the Google and Yahoo bulk-sender rules and do they apply to me?

In February 2024 Google and Yahoo introduced shared requirements for anyone sending more than 5,000 emails a day to their users, and they apply to your domain whether you send through a newsletter tool or your own server:

• Authenticate everything - SPF and DKIM must pass, and you need a DMARC record (even a monitoring-only p=none one) published.
• One-click unsubscribe - bulk marketing mail must let recipients opt out in a single click, honoured within 2 days.
• Stay under the complaint ceiling - keep your spam-complaint rate below 0.3%.
• The 5,000 threshold is per domain, not per campaign - totals across all your tools count toward it.

Even well under 5,000 a day, meet these rules anyway - they are simply what good deliverability looks like now.