Microsoft 365 outage locks users out of Outlook mail; Microsoft says recovery is holding

A Microsoft 365 outage on Friday, 13 November, locked business users out of their Outlook mailboxes and left email stuck in queues, in what British government agencies called a worldwide Microsoft failure. At 10 pm GMT on Friday (3.30 am IST on Saturday), Microsoft said recovery was holding but it would keep watching longer than usual because the impact had been so severe.

Update, Saturday, 14 November: Microsoft has since closed the incident for personal accounts. Its final note on its service status page, posted at 3.51 am GMT (9.21 am IST), said services had fully recovered and the backlog of email had been processed. Microsoft dates that incident from 10.05 am GMT on Thursday, 12 November, to 4.10 pm GMT on Friday, 13 November (9.40 pm IST). The incident for business customers was still listed as a service degradation at 5.37 am GMT (11.07 am IST) on Saturday, with Friday’s 10 pm GMT note still the latest.

What failed, and what kept working

The trouble sat in Exchange Online, the system behind work and school Outlook accounts. Mailboxes could be unreachable in Outlook on the web, on the desktop and on phones, and incoming mail could arrive late. Features that lean on Exchange were hit too: Teams calendar invites and meeting changes failed, Copilot Chat could refuse to load, Universal Print jobs could fail and Intune device enrolment was intermittently disrupted.

Teams kept handling calls, meetings, chats and channel posts, Microsoft said, and documents held in SharePoint itself could still be opened. For personal accounts, the company said at 8.03 pm GMT (1.33 am IST on Saturday) that queued mail was still being cleared and gave no time for full recovery. Outlook.com was shown as operational at 11.16 pm GMT (4.46 am IST).

British public services feel the strain

The Planning Inspectorate halted its digital appeals service and will keep new submissions closed over the weekend, aiming to restart on Monday, 16 November. The Maritime and Coastguard Agency said its email was hit but search and rescue was not, and told anyone in danger at the coast to dial 999 for the Coastguard. Companies House warned email replies could be slower.

The Intellectual Property Office said patent, trade mark and design rules allow extra time when email fails, with each request judged on its merits. The Insolvency Service said at 4.30 pm GMT (10 pm IST) that its email problems appeared to be easing.

Microsoft’s 10 pm GMT update (3.30 am IST) gave no cause. It had promised its next update for business customers by 2.30 am GMT (8 am IST) on Saturday, 14 November, but at 5.37 am GMT (11.07 am IST) its public status page still showed the 10 pm note as the latest. Engineers were then still tracking the email backlog, Microsoft said, so every message is delivered.