(Resumed) Users’ mailbox and calendar data may not sync as expected in the Outlook mobile client for iOS devices.

Microsoft issued an incident report on 30 Mar 2023 (Thu) about Microsoft Outlook on the web service degradation.

Users Affected Microsoft users
Start Time 29 Mar 2023 (Wed) 7:27 PM
End Time 1 Apr 2023 (Sat) 6:30 PM
User Impact Users’ mailbox and calendar data may not sync as expected in the Outlook mobile client for iOS devices. 
 Incident Details More info:

Microsoft continue to recommend that users avoid upgrading to Outlook for iOS version 4.2311.0.

Final status:

Microsoft’ve received the required approval from Apple and the latest build is now available to install within the App Store. Additionally, Microsoft’ve received feedback from the affected users confirming their email has started syncing and issue is no longer occurring.

Scope of impact:

Any user using Outlook for iOS version 4.2311.0 may experience impact.

Root cause:

A conditional access policy issue within a recent update, version 4.2311.0, is preventing users leveraging this version from syncing email and calendar data in the Outlook mobile client as expected on iOS devices.

Status Microsoft resolved the problem.

Last update by Microsoft: 1 Apr 2023 (Sat) 8:07PM