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Outage in Microsoft 365

Users may have been intermittently unable to access their Exchange Online mailboxes in some connection methods.

Minor
April 02, 2026 - Started about 5 hours ago

Incident Report

Title: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods User impact: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods. More info: This issue may intermittently impact some users who attempted to access the Exchange Online service through the Outlook mobile apps or the new Outlook for Mac desktop client. Current status: We've received reports from affected tenants that the impact scenario originally communicated through SHD EX1256020 is still ongoing. We're working to restart the Notification Broker service on affected portions of Exchange Online service infrastructure to remediate impact while we continue our analysis into the underlying root cause. Scope of impact: Impact may occur intermittently for some users accessing their Exchange Online mailboxes in the Outlook mobile apps or the new Outlook for Mac desktop client. This section may be updated as our investigation progresses. Next update by: Thursday, April 2, 2026, at 11:30 PM UTC
Components affected
Exchange Online

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Latest Updates ( sorted recent to last )
36 minutes ago - at 04/02/2026 11:15PM

Title: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods

User impact: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods.

More info: This issue may intermittently impact some users who attempt to access the Exchange Online service through the Outlook mobile apps or the new Outlook for Mac desktop client.

Current status: We're finalizing our process to restart the Notification Broker service across the affected infrastructure, which we anticipate may remediate the impact. In parallel, we're assessing options to implement long-term mitigation and telemetry to prevent further instances of impact while we continue our investigation into the underlying root cause.

Scope of impact: Impact may occur intermittently for some users accessing their Exchange Online mailboxes in the Outlook mobile apps or the new Outlook for Mac desktop client. This section may be updated as our investigation progresses.

Next update by: Friday, April 3, 2026, at 1:30 AM UTC

about 5 hours ago - at 04/02/2026 07:15PM

Title: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods

User impact: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods.

More info: This issue may intermittently impact some users who attempted to access the Exchange Online service through the Outlook mobile apps or the new Outlook for Mac desktop client.

Current status: We've received reports from affected tenants that the impact scenario originally communicated through SHD EX1256020 is still ongoing. We're working to restart the Notification Broker service on affected portions of Exchange Online service infrastructure to remediate impact while we continue our analysis into the underlying root cause.

Scope of impact: Impact may occur intermittently for some users accessing their Exchange Online mailboxes in the Outlook mobile apps or the new Outlook for Mac desktop client. This section may be updated as our investigation progresses.

Next update by: Thursday, April 2, 2026, at 11:30 PM UTC

source IsDown Widespread Microsoft service outages Reports started about 1 hour before official outage was reported

Users report Microsoft Outlook and Excel crashing, login issues, and data fetching problems in Office 365 starting from 4-1-26.

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