Microsoft is preparing to roll out broader corrective measures to contain a global outage that has disrupted several of its services for more than 11 hours. The company is monitoring servers where temporary fixes have been introduced and assessing their stability before restoring normal levels of traffic.

The latest recovery effort involves increasing the capacity of virtual machines, reducing pressure on affected infrastructure and identifying servers that have not successfully received recent network updates.

Microsoft said some machines remained in an unhealthy state and that configuration changes were not synchronising as expected. Engineers are therefore attempting to force those systems to update with the latest network settings in the hope of improving service availability.

The company plans to gradually allow more traffic through once it is confident that the affected servers can handle a limited volume of connections without further disruption. Additional fixes will be introduced as the infrastructure demonstrates greater stability.

Server overload identified as key problem

Microsoft's investigation has traced the disruption to a process used by affected servers to establish secure connections. The process became overwhelmed, preventing the servers from handling incoming requests.

To address the issue, the company is testing a configuration change on a smaller group of servers before extending it across the wider affected network. The recovery plan also includes restarting parts of the infrastructure.

Separately, Microsoft has started reversing a recent network configuration change that was introduced around the time the outage began. It is monitoring whether rolling back that update helps restore services.

Outlook, Copilot and other services affected

The disruption has affected multiple Microsoft 365 products and functions that rely on Exchange Online and its email infrastructure. Microsoft has clarified that features which do not depend on Exchange Online continue to operate.

Users may be unable to open their mailboxes through Outlook on the web or desktop, Exchange ActiveSync and REST-based connections. Email delivery could also be delayed.

Some Microsoft 365 administration pages may fail to load, while users could face problems accessing recently opened files within Microsoft 365 applications.

Copilot Chat has also been affected. Users may be unable to launch the service or receive responses through its web and desktop versions. Its ability to retrieve workplace information, including emails, calendars and files, may also be disrupted.

Other products and services reporting problems include Microsoft Planner, Microsoft To Do, Microsoft Purview, Microsoft Defender, Microsoft Graph, Power BI and Universal Print, along with certain Windows 365 functions.

Teams messaging and meetings largely continue

Microsoft Teams users may encounter problems with features connected to Exchange Online, particularly calendars and meeting scheduling.

However, the company said the platform's core messaging functions and online meetings remain largely operational. Files stored directly in SharePoint Online can also still be accessed.

The distinction means that while some connected features are unavailable or unreliable, not every Microsoft 365 service has been affected in the same way.

Recovery depends on server stability

Microsoft said its engineers are continuing to monitor the affected machines and evaluate the impact of the measures already introduced.

The company has not yet declared the disruption resolved. Its next steps will depend on whether the server fixes hold up under increased traffic, allowing it to progressively restore connections and extend corrective changes across the affected infrastructure.