The Microsoft office building at RheinauArtOffice in Cologne, Germany on September 11, 2025.
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Microsoft On Thursday, it said it was working to fix technical issues in Outlook that prevented it from sending and receiving email messages.
The incident happened in the middle of US business hours, leading people to resort to a snafu on social networks schools, government institutions and companies were busy with the break. The program represents the core of Microsoft 365 productivity software suites.
At 2:37 p.m. ET, the company said in an X message that it is investigating an issue affecting Outlook.
“Users may receive a ‘451 4.3.2 temporary server problem’ error message when trying to send or receive email through Outlook,” Microsoft said in an update to its online dashboard.
In addition, searches in the OneDrive cloud file storage app and SharePoint Online collaboration service may be slow or not work at all, the company said in a dashboard.
In an X message posted at 3:17 p.m. ET, Microsoft said it had determined that “part of its service infrastructure in North America” was not handling traffic properly and was working to fix the problem.
In a subsequent post at 4:14 p.m. ET, the company said it was rebuilding the affected infrastructure and redirecting traffic to other infrastructure to restore it.
Last July, the Outlook outage was prolonged More than 21 hours.
