The South African Revenue Service (SARS) has issued a warning to taxpayers following a global Microsoft service outage that has disrupted access to Outlook, Teams and other Microsoft 365 applications.
The disruption began on Thursday, 12 November, affecting businesses, government institutions and Microsoft users across several countries.
In a notice published on Friday, 13 November, SARS confirmed that Microsoft was experiencing a worldwide service interruption.
The revenue service said its technical teams were communicating directly with Microsoft to address the problem and would provide further updates as information became available.
SARS also apologised for the inconvenience and thanked affected users for their patience.
Microsoft Investigates Exchange Online Infrastructure Failure
The outage has been linked to Microsoft’s Exchange Online infrastructure, which supports the email services used by Outlook.
Microsoft’s investigation found that a process responsible for establishing secure connections on affected servers had become overwhelmed, preventing the servers from processing requests properly.
The situation was worsened when several servers unexpectedly became unavailable, increasing the workload on the remaining infrastructure.
Microsoft has been working to restart affected servers, make configuration adjustments and restore capacity across its network.
The company is also investigating a recent network configuration change that coincided with the start of the disruption.
Microsoft has stated that it has found no indication that malicious activity or a cyberattack caused the outage. However, a final report identifying the precise root cause has not yet been published.
Outlook, Teams and Other Microsoft Applications Experience Problems
Although Outlook has been among the services most visibly affected, the disruption has extended to other Microsoft applications that depend on Exchange Online.
Affected services and features include:
- Outlook: Users may experience difficulties accessing their inboxes through desktop, mobile and web applications. Some email deliveries may also be delayed.
- Microsoft Teams: Messaging and online meetings have largely continued functioning, but calendar access, meeting scheduling and connected features may experience interruptions.
- Microsoft 365 Copilot: Users may encounter problems accessing Copilot Chat and retrieving information from work emails, calendars and documents.
- SharePoint: Some connected functions may be disrupted, although direct access to files stored on SharePoint remains operational.
- Microsoft Defender: Certain security features, including Safe Links, may experience difficulties checking links contained in emails and messages.
The impact varies depending on how individual applications and features depend on Exchange Online services.
Microsoft Works to Restore Normal Operations
Microsoft has been attempting to bring affected servers back online and gradually restore normal traffic across its infrastructure.
The company has reported progress from its efforts to restart affected systems, although the restoration process and service stability remain ongoing.
Users may experience services returning gradually as infrastructure becomes available and applications reconnect.
The outage has affected services used by organisations for everyday communications, document management, meetings and administrative operations.
What the Microsoft Outage Means for South African Taxpayers
SARS has not confirmed whether its own online platforms, including the eFiling system, have been affected by the Microsoft disruption.
Its public warning specifically highlights possible access problems involving Outlook, Teams and other Microsoft 365 applications.
South African taxpayers who depend on affected Microsoft services for work-related communications or accessing information may experience interruptions while the outage continues.
SARS said it would communicate additional updates as more information about the disruption becomes available.
