Microsoft 365

Title: Users can't reply or reply-all to email messages sent to Microsoft 365 groups in Exchange Online User impact: Users can't reply or reply-all to email messages sent to Microsoft 365 groups in Exchange Online. Current status: We're investigating a potential issue with Exchange Online and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Some users’ email messages may not be quarantined and fail to be stored in the quarantine folder User impact: Users’ email messages may not be quarantined and might fail to be stored in the quarantine folder. More info: Some legitimate email messages are not being delivered to the intended recipient and cannot be released through the normal Microsoft Defender quarantine workflow. Current status: We're reviewing support case details to determine our next troubleshooting steps. Scope of impact: This issue may impact users attempting to have email messages quarantined in Exchange Online. This section may be updated as the investigation progresses. Next update by: Thursday, September 24, 2026, at 1:30 PM UTC

Title: Users can't reply or reply-all to email messages sent to Microsoft 365 groups in Exchange Online User impact: Users can't reply or reply-all to email messages sent to Microsoft 365 groups in Exchange Online. Current status: We're investigating a potential issue with Exchange Online and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Some users’ email messages may not be quarantined and fail to be stored in the quarantine folder User impact: Users’ email messages may not be quarantined and might fail to be stored in the quarantine folder. More info: Some legitimate email messages are not being delivered to the intended recipient and cannot be released through the normal Microsoft Defender quarantine workflow. Current status: We're reviewing support case details to determine our next troubleshooting steps. Scope of impact: This issue may impact users attempting to have email messages quarantined in Exchange Online. This section may be updated as the investigation progresses. Next update by: Thursday, September 24, 2026, at 1:30 PM UTC

Title: Potential issues accessing mailboxes via one or more connection methods User impact: Users may experience errors or failures when accessing their mailbox via one or more Exchange Online connection methods. Current status: We're investigating a potential issue and checking for impact to your organization. We'll provide an update within 60 minutes.

Title: Some users may experience unexpected application crashes for Microsoft Teams on macOS devices User impact: Users may experience unexpected application crashes for Microsoft Teams on macOS devices. More info: Impact is specific to users who have updated to their macOS devices to version 27.2 beta. Current status: We've identified a significant increase in Microsoft Teams application crashes affecting macOS devices on version 27.2 beta and are investigating the underlying cause. We're continuing our analysis of crash telemetry and related diagnostic data to determine the source of impact and develop a remediation plan. Scope of impact: Impact is specific to users experiencing unexpected application crashes for Microsoft Teams on version 27.2 beta macOS devices. Next update by: Friday, September 18, 2026, at 3:30 PM UTC

Title: We're looking into a potential problem impacting Microsoft Teams User impact: We're looking into a potential problem impacting Microsoft Teams Current status: We're investigating a potential issue with Microsoft Teams and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Users may be unable to load SharePoint Online sites or pages and receive an error message User impact: Users may be unable to load SharePoint Online sites or pages and receive an error message. More info: The error message states: "Sorry, something went wrong: Thread was being aborted." Current status: We're investigating a potential issue with SharePoint Online and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Some users in the United States may be unable to access Microsoft 365 services User impact: Users in the United States may be unable to access Microsoft 365 services. Current status: We're reviewing service monitoring telemetry and associated reports to isolate the root cause, in order to develop a remediation plan. Scope of impact: Impact is specific to users in the United States attempting to access Microsoft 365 services. This information may be updated as our investigation continues. Next update by: Wednesday, September 16, 2026, at 3:30 PM UTC

Title: Some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients User impact: Users may intermittently be unable to launch Microsoft Teams from the web or desktop clients. Current status: We're investigating a potential issue in which some users may intermittently be unable to launch Microsoft Teams from the web or desktop clients and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Some users are unable to send or receive Exchange Online email through the native iOS mail app User impact: Users are unable to send or recieve Exchange Online email through the native iOS mail app. Current status: We're investigating a potential issue with Exchange Online and checking for impact to your organization. We'll provide an update within 60 minutes.

Title: Users may experience delays receiving email messages from external domains in Exchange Online User impact: Users may experience a delay in receiving email messages from external domains in Exchange Online. More info: Users may experience intermittent “Server busy” errors, affecting multiple mailboxes. Current status: We're investigating a potential issue and checking for impact to your organization. We'll provide an update within 60 minutes.

Title: Some users may see the Teams chat icon is missing when using the new chat and channels experience in Microsoft Teams User impact: Users may see the Teams chat icon is missing when using the new chat and channels experience in Microsoft Teams. More info: All Microsoft Teams clients are impacted. Current status: We're investigating a potential issue with Microsoft Teams and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Users may be unable to join calls or meetings in Microsoft Teams for Mac User impact: Users may be unable to join calls or meetings in Microsoft Teams for Mac. Current status: We're investigating a potential issue with Microsoft Teams and checking for impact to your organization. We'll provide an update within 30 minutes.