Google, Yahoo, and Microsoft Tighten Bulk Email Rules—What Marketers Must Change
Google and Yahoo began throttling bulk senders over 5k daily emails on Feb 1 2024; non‑compliant traffic now gets temporary errors and will be fully rejected by April. Microsoft follows suit, routing or rejecting high‑volume messages to Outlook.com from May 5 2025. Marketers must upgrade SPF/DKIM/DMARC and monitor spam rates to keep inbox placement.