A cloud-based service included in Microsoft 365, delivering scalable messaging and collaboration features with simplified management and automatic updates.
Microsoft is investigating an active Exchange Online incident, EX1550543, but no confirmed restoration time has been published yet.
Check the latest update
- Microsoft 365 administrator: Open the Microsoft 365 admin center → Health → Service health → Active issues Microsoft is working on, then select EX1550543. Its details show the status, user impact, affected services, and Microsoft’s latest progress update. Service Support and Helpdesk administrators can also view service health.^1^
- Unable to access the admin center: Check the public Microsoft service health status.^2^
- End user: Contact the Microsoft 365 administrator for the organization, because the admin-center entry can contain tenant-specific information unavailable publicly.
Reports currently associate the disruption with mailbox-access failures, particularly in the Americas, but Microsoft has not provided a firm ETA.^3^
If the admin dashboard lists the incident for the tenant, avoid changing Outlook profiles or account settings while recovery is underway. If EX1550543 is not listed for the tenant, use Service health → Report an issue so Microsoft can correlate the report with other affected organizations.^1^
References