Step-by-step tutorial to deploy MTA-STS on Microsoft 365, Google Workspace, and Cloudflare. MX patterns, policy file, hosting, and validation included.

December 2025

Illustration: 1.1.1.1 (Cloudflare), a public DNS resolver with DoH/DoT/ODoH options and a privacy focus

CaptainDNS · December 23, 2025

Cloudflare DNS (1.1.1.1): privacy, DoH/DoT, deployment

1.1.1.1 is Cloudflare's public DNS resolver. Here's how to use it properly (addresses, DoH/DoT/ODoH, tests, pitfalls) and deploy it.