Microsoft 365 ships open. A new tenant will happily let anyone sign in from any device,
anywhere in the world, with a password alone — and it will do it without generating a
single complaint. Nothing breaks. That's the difficulty. There is no error message for a
tenant that has no conditional access policies; there's just a quiet gap between what you
assume is happening and what's actually enforced.
The gap usually shows up in the same few places. MFA is on for most people, but not the
service account nobody remembers creating. Legacy authentication is still enabled because
turning it off might break the scanner in accounting. Personal phones sync company mail
with nothing in the way. Six people are Global Administrators because that's what "make
them an admin" did at the time.
None of that is negligence. It's what happens when a
tenant
grows one request at a time over five years and nobody's job was to look at the whole
thing.