Office 365 integration FAQs
You can use Automatic WS-Federation to configure multiple Office 365 domains in one app instance. See Federate multiple Office 365 domains in a single app instance.
However, if you are using Manual (PowerShell) WS-Federation, you need to configure a separate instance of the Microsoft Office 365 application within Okta for each domain you have in your office tenant. For example, if you have five domains under your office tenant, you would have five office apps in Okta, each pointed to the Microsoft 365 tenant but set with a different domain. See Add Office 365 to Okta.
They can but we can't secure them through MFA since they don't use Modern Authentication.
We strongly recommend disabling these protocols in your Office 365 tenant. To disable these legacy protocols in your Office 365 tenant, refer to the Microsoft Support documentation.
It’s probably because you haven’t set up Okta for provisioning users into Office 365. See Provision users to Office 365.
Get started with Office 365 provisioning and deprovisioning
Get started with Office 365 sign on policies