If the domain's MX record points somewhere other than M365, mail isn't flowing through Exchange Online Protection — meaning Defender for Office, anti-phish, Safe Links, and the rest of M365's mail filtering aren't actually inspecting inbound mail. Often unintentional after a migration.
A scan reports where your tenant stands on this check — pass, fail with a step-by-step fix, or not applicable if your licensing doesn’t include the feature. When Tenant Strike can’t read a setting with read-only access, it says unverified and gives you a one-command way to confirm it yourself — it never guesses.
Check your own tenant
Is your tenant covered on "route mail through microsoft 365"?
One read-only scan answers it — this check and every other one in the catalog, each with a plain-English fix. 7-day Pro trial, no credit card.