Good afternoon, Users may be unable to connect to their mailboxes in Exchange Online through multiple connection methods
Issue ID: EX1550543 Affected services: Exchange Online Status: Service degradation Issue type: Incident Start time: Nov 12, 2026, 11:17 AM EST
User impact Users may be unable to connect to their mailboxes in Exchange Online through multiple connection methods.
More info Potentially impacted connection methods may include: - Outlook on the web - Messaging API (MAPI) - Exchange ActiveSync (EAS) - Representational State Transfer (REST) API
Scope of impact This issue may affect users in North America, Latin America, Canada, and Chile.
Current status Nov 12, 2026, 12:45 PM EST We’ve identified connectivity errors occurring on a portion of Exchange Online infrastructure which receives and processes users’ access requests. We’ve collected networking logs to review to further investigate the source of these errors and confirm our next steps. Next update by: Thursday, November 12, 2026 at 3:00 PM EST
History of updates Nov 12, 2026, 11:55 AM EST We’re reviewing service health telemetry information to identify and isolate any errors contributing to impact for further investigation. Nov 12, 2026, 11:20 AM EST We're investigating a potential issue and checking for impact to your organization. We'll provide an update within 60 minutes.
Posted Nov 12, 2026 - 13:02 EST
This incident affects: Managed IT Services (Email / Office 365).