Overview
As part of our ongoing security efforts, we have made a recent change to Certificate-Based Authentication (CBA) behavior for Exchange ActiveSync. The enhancement is designed to support TLS...
Updated Oct 10, 2025
Version 1.0
Blog Post
1 MIN READ
Exchange Online ActiveSync Certificate-based Authentication endpoint changes
"For most Exchange ActiveSync clients, this change will be seamless. The client traffic will be implicitly redirected to the new CBA endpoints without any user action required." - Well, that broke this last week. 100% of all of our iOS native email clients just stopped working. Updating things to point to the new hostname. MS why is this information so hard to find!!?? This never came across the tenant announcements.