MTA-STS
A policy that tells mail servers to require TLS for inbound delivery.
Mail Transfer Agent Strict Transport Security lets a domain publish a policy requiring encrypted SMTP connections from supporting senders. It helps prevent downgrade attacks where delivery falls back to unencrypted transport.
reading this as growth and lifecycle teams
Growth work lives or dies on targeting and measurement. What matters is whether behavioral triggers can be built without engineering time, whether the event stream supports attribution past the open, and whether deliverability holds when broadcast volume shares a reputation with product email.
Applied to mta-sts, that means weighing scheduling, event stream, deliverability, and operating track record ahead of the rest, against behavior-triggered journeys, broadcasts, and winback campaigns measured on revenue.