Security News > 2022 > September > Microsoft to retire Exchange Online client access rules in a year
Microsoft announced today that it will retire Client Access Rules in Exchange Online within a year, by September 2023.
CARs are sets of conditions, exceptions, actions, and priority values that allow Microsoft 365 admins to filter client access to Exchange Online based on many factors.
In short, once configured, they help control who can access what resources in an Exchange Online organization.
"We will send Message Center posts to tenants using client access rules to start the planning process to migrate their rules."
Until September 2023, Microsoft plans to help migrate all remaining tenants from CARs to use new access control features like continuous access evaluation.
As Redmond explains, the switch to CAE access control to Exchange Online resources is designed to add extra resiliency by proactively terminating active user sessions and ensuring tenant policy change enforcement in almost real-time.