Will mailbox providers centralize standards?

Trend toward alignment is visible: **Gmail** and **Yahoo** coordinated bulk sender requirements in 2024. But complete centralization is unlikely. Each **MBP** has different user bases, business models, and competitive incentives to differentiate.

Likely evolution: more coordination on foundational requirements (authentication, basic practices), continued variation in filtering approaches, and independent innovation in features. Standards will converge where everyone benefits; approaches will differ where competitive advantage exists.

For senders: plan for baseline requirements becoming universal while maintaining flexibility for provider-specific optimization. Authentication standards are converging; engagement-based filtering will remain provider-specific.