A massive Microsoft outage that disrupted email and online services across Canada was showing signs of improvement Friday morning, but users may still run into problems as the company works to restore its systems.
Microsoft says it has made further progress restoring its affected infrastructure, with traffic gradually returning and improvements reported in mailbox access and delayed email delivery.
The outage began Thursday, and has affected Outlook, Microsoft 365 and several other services around the world. The disruption has stretched beyond 12 hours, affecting businesses, government operations and other organizations that rely on Microsoft's cloud-based systems.
In Ontario, Unity Health Toronto declared a Code Grey after losing the ability to reliably send and receive emails. The hospital network says patient and resident care are not affected and its hospitals remain open.
Municipalities have also reported disruptions. Oshawa warned that some city services and response times could be affected, although 911 calls were not impacted. Clarington reported problems sending and receiving email, while Thunder Bay also reported disruptions to email and online applications.
Microsoft reports progress restoring services
In its latest update Friday morning, Microsoft said recovery actions have been completed across portions of its affected infrastructure and traffic is gradually returning.
The company reported improvements in mailbox access and the processing of delayed emails. However, it cautioned that some intermittent problems could continue as it works to restore the remaining infrastructure and increase capacity.
Microsoft has been applying patches to affected systems and restarting servers in an effort to bring them back online.
The company says it is seeing improved server stability after applying an upstream authentication and routing configuration patch. It is expanding that fix to additional infrastructure, particularly systems supporting regions entering peak business hours.
There is still no confirmed timeline for a complete recovery.
What caused the Microsoft outage?
The disruption primarily affected Exchange Online, the technology behind Microsoft's email services.
Microsoft's investigation found that a process on affected servers responsible for establishing secure connections was becoming overwhelmed. That caused servers to stop processing requests, leaving the remaining infrastructure struggling to handle the load.
The company has also been investigating network configuration changes that coincided with the start of the outage.
While the problems spread to several Microsoft products, not every feature was affected in the same way.
Teams' core messaging and online meeting functions have remained largely operational. However, features that depend on Exchange Online, including calendar access and meeting scheduling, may still fail.
Accessing files stored directly in SharePoint Online has also remained functional, although other features connected to Exchange Online have been affected.
Microsoft says it has no evidence that malicious activity or a cyberattack caused the disruption.
What Canadians should do while recovery continues
Anyone still having trouble accessing Outlook or other Microsoft services should consider using alternative ways to communicate until systems are fully restored.
Phone calls and text messages remain the simplest options for urgent communications. Businesses and organizations may also want to use alternative messaging platforms while Microsoft works through the remaining problems.
Documents already downloaded or saved directly to a computer may still be accessible without a connection to Microsoft's cloud services.
Anyone trying to contact a hospital, municipality or government department should check its website or social media channels for alternate contact information. Calling directly may be the best option if the matter is urgent.
Users should also avoid repeatedly sending emails that appear to be stuck. Messages may be delayed rather than lost, potentially resulting in duplicate emails once delivery catches up.
Microsoft says it will continue monitoring the recovery and expanding its fixes until services are fully restored. Users can follow updates through the company's Microsoft 365 service status page.
