Mailboxes Won’t Open, Meeting Scheduling Disrupted...MS 365 Hit by Outages in Many Areas

[Financial News] Microsoft (MS)’s cloud email service suffered an access outage on the 12th (local time), disrupting users in the United States, the United Kingdom, Japan, Australia and elsewhere. Users experienced problems accessing Outlook mailboxes and sending and receiving email, while issues also affected meeting scheduling in Teams and Copilot’s work-data lookup feature, both linked to the same email system.
On the 13th, online service outage tracker Downdetector reported that around 1:30 p.m. on the 12th (local time), reports of Outlook-related outages in the United States had topped 120,000. That was around 3:30 a.m. on the 13th in Korea. Reports related to MS 365 numbered at least 46,000, while Teams had around 3,000. Outlook users reported being unable to open their mailboxes or experiencing delays in sending and receiving email.
According to an outage report MS sent to customers, the problem occurred in its cloud email service, Exchange Online. Some users could not open their mailboxes in Outlook for the web or desktop, and some Teams features, including viewing meeting schedules and sending invitations, encountered errors. Joining Teams meetings and group chats worked normally for the most part. Some users also had difficulty loading chats or getting responses in MS 365 Copilot.
Businesses and public agencies were also affected. Reuters reported that the U.S. House of Representatives said its technical staff had begun working with MS to address the outage after users on its system were affected. Japan’s government IT infrastructure was also affected.
MS said via its official X account that it was investigating mailbox access problems with Exchange Online. In a subsequent notice to customers, it explained that many servers had unexpectedly gone out of service, concentrating the load on the remaining servers. MS determined that the affected servers had failed automated health checks and tested configuration changes while redistributing access traffic and restarting servers.
MS said services in some areas had temporarily recovered, but the recovery was not stable, and that it was taking additional measures, including increasing server processing capacity.

[email protected] Jang Min-kwon Reporter