The key facts

  • Microsoft reported Outlook mail unavailability, first in the US and America, then in any region
  • The cause of the outage was not stated; the company cited increased load on part of its infrastructure
  • In September there was already a multi-day Microsoft 365 outage caused by a 'baseline authentication configuration'

Outlook became unavailable to users

Microsoft reported that its Outlook email service is experiencing an outage that prevents users from accessing their mailboxes. Initially, the problem was recorded as affecting the US and America, but the company then broadened the description to 'any region'.

What is known about the cause

Microsoft did not state the specific cause of the outage. The admin center, where the company promised to post updates, was itself unavailable at the time the news was published. In a message for users who could not open it, Microsoft said that part of its infrastructure was experiencing 'increased load' and that it was 'redistributing connection traffic across a broader global infrastructure to balance the load.' It remained unclear to what extent the outage affected the company's other services.

Second major incident in two months

This is already the second major incident in a short period: in September, an outage led to the multi-day unavailability of the Microsoft 365 online suite, which includes Outlook. At the time, Microsoft blamed a 'baseline authentication configuration' that prevented users from accessing the service. Publications did not report whether the current outage was connected to the September incident.