The US government is pushing federal agencies and private corporations to adopt the Modern Authentication method in Exchange Online before Microsoft starts shutting down Basic Authentication from the first day of October.
In an advisory [PDF] this week, Uncle Sam's Cybersecurity and Infrastructure Security Agency (CISA) noted that while federal executive civilian branch (FCEB) agencies – which includes such organizations as the Federal Communications Commission, Federal Trade Commission, and such departments as Homeland Security, Justice, Treasury, and State – are required to make the change, all organizations should make the switch from Basic Authentication.
"Federal agencies should determine their use of Basic Auth and migrate users and applications to Modern Auth," CISA wrote. "After completing the migration to Modern Auth, agencies should block Basic Auth."