In a series of posts on the social platform X, the company said it was investigating the issue, which affected various Microsoft 365 services.

“We’ve identified a potential cause of impact and have reverted the suspected code to alleviate impact,” Microsoft said in the posts, which were published by a company page dedicated to addressing incidents tied to its office software programs.

The company said in the afternoon that its tracking indicated that “a majority of impacted services are recovering following our change.”

Earlier some users took to social media to say they were unable to access their Outlook email accounts.

Data from Downdetector, which tracks outages, showed thousands of reports from users.

Outage reports for Microsoft 365, and Outlook in particular, peaked around 4 p.m. Eastern Standard Time before dropping off, and some users began saying their access was restored.

Earlier this week the communications platform Slack also experienced an outage that left thousands of users unable to use the service.