The state of email infrastructure: what 660K DNS records reveal in 2026

The conventional wisdom is that Google Workspace and Microsoft 365 dominate business email. I pulled the DNS records of every domain in Tranco top-1M to check. Their combined share: 37.94% . The other ~62% — half a million domains — live somewhere else: hosted at registrars, in regional providers, on cPanel installs at small hosters, or on actual self-managed mail servers. The "duopoly" framing is a thing people say, not a thing the data shows. This post is about what you actually find when you