Why has Microsoft's Outlook outage dragged on for so long?

Outlook problems began on Thursday, and 130,000 reports piled up on Downdetector, with many users unable to send or receive email.

Within an hour, problems were logged in 74 countries and territories, and Teams and Copilot were hit too.

Microsoft said traffic imbalances and heavy load on part of its infrastructure, plus servers that failed automated checks, and it saw no sign of malicious action. Its fixes fell short, so it was redirecting traffic away from affected servers. After about 8 hours, the disruption was still unresolved.

By midnight, reports had only fallen to 37,000. Press reports said many services remained unreachable on Friday morning, including sensitive government areas.