Microsoft Fixing Exchange Online Issue That Incorrectly Quarantined Mailboxes
Summary
Microsoft says an infrastructure change caused excessive memory use and incorrect Exchange Online mailbox quarantines starting July 19, disrupting email and calendar access. Cleanup was 72% complete in the latest update, with no full-recovery timeline.
Key points
- Microsoft tracked the incident as EX1436407; it began July 19 and remained unresolved in the latest update.
- Affected users reported problems sending and receiving email and accessing calendars.
- Microsoft attributed the incorrect quarantines to excessive memory use and an out-of-memory condition following an infrastructure change.
- The issue recurred after a similar incident, EX1434354, and required additional remediation.
- Cleanup of excess indexing data reached 72% completion; Microsoft was gradually removing mailboxes from quarantine while validating memory levels.
- Microsoft had not provided a full-remediation timeline or disclosed the affected regions or customer count.
Article Details
- Event Type
- Exchange Online service incident caused by an infrastructure change and excessive memory use
- Impact
- Some customers' mailboxes were incorrectly quarantined, disrupting email delivery and calendar access. Microsoft reported that cleanup was 72% complete in its latest update; the number of affected customers and regions was not disclosed, and no full-remediation timeline was provided.