M365 Service Health Notification

Exchange Online service alert Incident information Title: On-premises users leveraging hybrid modern authentication can't sync with Outlook for iOS and Android ID: EX218694 Status Service Restored Details Title: On-premises users leveraging hybrid modern authentication can't sync with Outlook for iOS and Android User Impact: Users may have been unable to sync messages with the Outlook mobile app if the mailbox was hosted on-premises. More info: As the fix progressed, users would have needed to re-add their accounts in their Outlook mobile app for the fix to take effect. Final status: We've confirmed that the fix has been completely deployed to the affected environment and our testing indicates that mail is now syncing as expected. Scope of impact: This issue only impacted users hosted on infrastructure where the regression was introduced. All other users would not have been impacted. Start time: Monday, July 6, 2020, at 3:00 PM UTC End time: Tuesday, July 21, 2020, at 10:00 PM UTC Root cause: A recent update exposed a code regression that was causing the Sent Items folder for on-premises users using hybrid modern authentication to grow inorganically, resulting in the mailbox reaching the quota limit and users being unable to sync in the Outlook mobile app. Next steps: - We're reviewing our update procedures to better identify similar issues during our development and testing cycles. This is the final update for the event. Thank you, The Microsoft team To customize what's included in this email, who gets it, or to unsubscribe, set your Service health preferences. If you are receiving this email because your Admin added you as a recipient, please contact your Admin to unsubscribe. Microsoft respects your privacy. Review our online Privacy Statement. Microsoft Corporation One Microsoft Way Redmond, WA USA 98052