SARS warns of global Microsoft outage affecting Outlook and Teams

The South African Revenue Service (SARS) has warned taxpayers of a global Microsoft service outage that could affect access to Outlook, Teams and other Microsoft 365 applications.

The disruption, which began on Thursday, 12 November, has affected businesses, government institutions and Microsoft users in several countries.

In a notice published on Friday, 13 November, SARS confirmed that Microsoft was experiencing a global service disruption.

“Our technical teams are engaging directly with Microsoft to address the disruption. Further updates will be communicated as information becomes available,” the revenue service said.

SARS apologised for the inconvenience and thanked users for their patience.

What caused the Microsoft outage?

The disruption is linked to Microsoft’s Exchange Online infrastructure, which provides the underlying email services used by Outlook.

Microsoft’s investigation found that a process responsible for establishing secure connections on affected servers was becoming overwhelmed, causing servers to stop processing requests.

The problem was compounded by a number of servers becoming unexpectedly unavailable, placing additional pressure on the remaining infrastructure.

Microsoft has been working to restart affected servers, introduce configuration changes and restore capacity across its network.

The company has also been investigating a recent network configuration change that coincided with the beginning of the disruption.

Importantly, Microsoft has said it has no indication that malicious activity or a cyberattack caused the outage.

The company has not yet published a final report detailing the root cause.

Which Microsoft services are affected?

Although Outlook has been among the most visibly affected services, the disruption extends beyond email.

Microsoft 365 applications and services that depend on Exchange Online have also experienced problems.

These include:

• Outlook: Users may be unable to access their inboxes through desktop, mobile or web applications. Email delivery may also be delayed.
• Microsoft Teams: Core messaging and online meetings have largely remained functional, but calendar access, meeting scheduling and certain connected features may fail.
• Microsoft 365 Copilot: Users may experience problems accessing Copilot Chat and retrieving information from work emails, calendars and files.
• SharePoint: Some connected features may be affected, although direct access to files stored in SharePoint remains functional.
• Microsoft Defender: Certain security features, including Safe Links, may experience problems verifying links contained in emails and messages.

The extent of the disruption varies depending on which services and features rely on Exchange Online.

Microsoft working to restore services

Microsoft has been working to bring affected servers back online and gradually restore normal traffic.

The company has reported positive results from its efforts to restart affected infrastructure, although service stability and recovery remain ongoing concerns.

Users may experience a gradual restoration of services as servers return to operation and applications reconnect.

The disruption has highlighted how heavily businesses and government institutions rely on Microsoft’s cloud-based services for everyday communication, document management and administrative operations.

What does this mean for South African taxpayers?

SARS has not specified whether its own online services, including its eFiling platform, have been affected by the Microsoft disruption.

Its warning specifically concerns possible access problems involving Outlook, Teams and other Microsoft 365 applications.

Taxpayers who rely on affected Microsoft services for communication or accessing work-related information may experience inconvenience while the disruption continues.

SARS has indicated that further updates will be communicated as more information becomes available.