Users may be unable to connect to multiple Microsoft 365 services

Update timeline

1. investigating Nov 12, 2026, 06:10 PM UTC

   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 Current status: 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. Scope of impact: This issue may affect users attempting to access their mailbox in Exchange Online using the affected connection methods. Next update by: Thursday, November 12, 2026, at 8:00 PM UTC

2. investigating Nov 12, 2026, 06:32 PM UTC

   Title: Users may be unable to connect to multiple Microsoft 365 services User impact: Users may be unable to connect to multiple Microsoft 365 services. More info: Potentially impacted services include: - Exchange Online - Microsoft Teams - SharePoint Online - Microsoft Copilot 365 - Microsoft Defender XDR Current status: We’re investigating an issue impacting multiple Microsoft 365 services and we've determined the affected infrastructure is experiencing elevated load across multiple regions, which is likely contributing to the connectivity errors. We're restarting and repairing impacted portions of this infrastructure to restore capacity, and reviewing an unexpected increase in a specific type of service traffic to determine whether it's contributing to the elevated load. In parallel, we're evaluating options to redirect traffic to alternate infrastructure to expedite relief. Scope of impact: This issue may affect users attempting to access the affected Microsoft 365 services. Next update by: Thursday, November 12, 2026, at 8:30 PM UTC