Microsoft said it was working to restart portions of the affected infrastructure.
Microsoft Corp said it was investigating issues with email service Outlook as users in North America faced problems with accessing, sending or searching emails on the platform.
There were more than 2,000 incidents of people reporting issues with Outlook late Tuesday at about 23:10 ET, according to Downdetector.com, which tracks outages by collating status reports from sources, including user-submitted errors on its platform.
The web monitoring firm showed that reports dropped to 351 incidents of people raising complaints as of 2:10 ET.
"Users primarily hosted in the North American region attempting to access Outlook.com may be unable to send, receive, or search email. Additional functionality such as Calendar consumed by other services such as Microsoft Teams would also be affected," Microsoft said in an update on its status page.
A "recent change" led to the issue and the company was working to restart portions of the affected infrastructure in order to restore service, Microsoft said in a tweet.
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