What is known about the issues with Outlook and the Microsoft suite

On Thursday 12 November, between 6.15 pm and 7 pm in Italy (12.15 pm and 1 pm on the east coast of the United States), the Downdetector outage monitoring service reported that a huge number of users were experiencing problems with Microsoft Outlook, the programme used for email, calendars and other online activities: there were 130,000 reports on the site in the United States and over 1,000 in Italy. This figure should be multiplied by roughly 100, given that, on average, only 1.2 per cent of those experiencing problems report them to the monitoring site.

Microsoft has reported a service disruption affecting many of its products: from the Microsoft 365 suite to Teams and Copilot. The disruption, which according to the company could affect business and private users in ‘any region’, lasted at least four hours, but the problems continued for hours and, as of Friday 13th (Italian time), had not yet been resolved.

Microsoft initially announced that it had detected that servers in various parts of the world were handling a very high volume of traffic, later specifying that “the overload was not caused by an increase in traffic, but by a number of servers that were unexpectedly unavailable, overloading the remaining infrastructure”. At around 13.14 US Eastern Time, Microsoft stated that it had begun redistributing connection traffic across its global infrastructure to help balance the load, and that it had restarted the affected servers to restore their operation.

What happened?