Improvements are being made after several Microsoft 365 applications, including Outlook and OneDrive.
Thousands of people around the world are affected by the outage.
Microsoft Office 365, Microsoft Teams, Outlook.com, OneDrive, Exchange, Azure and SharePoint are not available according to DownDetector.
“We are investigating a problem that affects access to several Microsoft 365 services,” Microsoft said early Tuesday on Twitter.
In a status update, Microsoft said, “Existing customer sessions are not affected and any user logged into an existing session can continue their sessions.”
In the update, Microsoft said improvements were observed for several services after mitigation steps were applied.
“Our mitigation strategy has been successful in allowing users to log into the previously affected services,” said Microsoft.
“Our internal monitoring has confirmed this recovery and we have received positive confirmation from customer reports.
“We will continue to monitor the service and provide full recovery updates to the remaining affected users.”
The company previously said rolling back a recent change did not mitigate the impact as expected.
“We are working on exploring additional options for mitigation,” the company said.