Is Microsoft 365 down? What's fixed, what's still broken
Is Microsoft 365 down right now? Mostly recovered, not fully closed. As of Wednesday morning, Microsoft's own telemetry shows service availability holding stable above 99%, though the company has kept the incident open while it finishes remediation work (NHSmail Support, today).
What started Monday as an Exchange Online and Outlook problem widened within hours into a suite-wide Microsoft 365 outage touching OneDrive, SharePoint, Teams, and Copilot (Kobaran, yesterday; TechCrunch, yesterday). Downdetector logged Outlook complaints jumping from around 37 reports to more than 6,000 within a short window Monday morning, the kind of curve that signals a genuine breakage rather than a blip (Kobaran, yesterday).
Reports of Outlook down and OneDrive down mostly trace back to Microsoft 365 Business and Enterprise accounts. The situation right now reads less like a yes-or-no answer and more like a status report.
Is Microsoft 365 down right now?
Recovered for most users. Microsoft's telemetry shows availability holding steady above 99%, and the company expects the majority of users are no longer seeing impact (NHSmail Support, today).
Still degraded for some functions. Search remains the one piece visibly lagging behind mail flow, with fixes still rolling out into Tuesday (Computerworld, yesterday). NHSmail's incident notice categorizes the issue as a service degradation affecting Exchange Online specifically, since it remains the most impacted component even now (NHSmail Support, today).
Officially open. The incident status is still marked ongoing, with Microsoft's next scheduled update not due until 4:30 p.m. UTC today (NHSmail Support, today). Microsoft's own language points the same direction: the company says it has entered "a period of extended monitoring to ensure a full resolution," which in practice means the fix is holding but Microsoft isn't ready to close the file (TechCrunch, yesterday).
What caused the Microsoft 365 outage?
Microsoft has pinned the blame on "an issue within a core authentication configuration used by multiple Microsoft 365 services" (NHSmail Support, today). In plainer terms, a misconfiguration kept authentication components from deploying correctly across part of Microsoft's infrastructure (Kobaran, yesterday; Computerworld, yesterday).
The timeline shows how the picture shifted hour by hour. Microsoft began investigating a rise in Exchange Online failure reports at 11:55 a.m. UTC Monday, and by 12:33 p.m. UTC had isolated a common failure pattern tied to authentication and protocol connectivity (Computerworld, yesterday). About an hour after that, Microsoft said it had identified a potential corrective action and was evaluating how to deploy it. Roughly two hours after isolating the failure pattern, the company confirmed the problem had spread beyond Exchange Online to other Microsoft 365 services, dating the start of that broader incident to 3:08 p.m. UTC (Computerworld, yesterday).
That escalation tracks with what Exchange Online actually does. It's the backend engine behind Outlook's email, calendar, and contacts, the plumbing most users never think about because it usually just works (Kobaran, yesterday). When the shared authentication layer underneath that plumbing falters, the failure doesn't stay contained to one pipe. It backs up into every service drawing from the same layer, which is why one broken dependency showed up as different symptoms across different apps instead of as a single, obvious failure.
Why are Outlook and OneDrive not working? What else is affected
The symptoms varied by service, and none of them amounted to a total blackout.
Outlook and Exchange Online: delayed or failed sending and receiving, mailbox search failures, and authentication errors when connecting (NHSmail Support, today).
OneDrive for Business and SharePoint Online: trouble loading account and storage info, search results, recent files, and shared content, plus some sync and mobile-upload failures (Cloud Admin Hub, live status mirror).
Teams: calendar, search, and presence functions all showed problems, part of the same wave of degraded services tied to the authentication issue (Computerworld, yesterday).
Copilot: prompts that needed Microsoft 365 data, like pulling in email content, could fail outright, since the assistant depends on the same services experiencing problems (Computerworld, yesterday).
The disruption reached further than the apps most people notice first. Microsoft's status page also listed Purview, Defender XDR, the Microsoft 365 admin center, and Universal Print among the affected services, covering everything from compliance tools to print-job submission (TechCrunch, yesterday).
One distinction is worth keeping straight. The incident notices describe Business and Enterprise services specifically; they don't establish any impact on personal Outlook.com or consumer OneDrive accounts. Anyone on a work or school account may have been affected, though not every organization or every user necessarily was.
How to check Microsoft 365 service status and what to do
If problems persist, skip the guesswork. Check Microsoft 365 Service Health in the admin center, or an organization's IT status page, where Microsoft has been posting incident IDs like EX1464935 and MO1465074 directly to affected tenants (NHSmail Support, today).
There's one confirmed workaround worth knowing. For SharePoint sites blocked by Authentication Context errors, clearing browser cookies, visiting the root site collection before the direct link, or opening the page in a new tab has helped some users get through, according to a live status mirror tracking Microsoft's service communications (Cloud Admin Hub, live status mirror).
Delayed mail isn't necessarily lost mail. Microsoft has warned that some organizations will take longer to drain backlogged message queues even after mail flow itself recovers, so a slow inbox right now points more to a backlog than a missing message (Computerworld, yesterday).
What's still unresolved
Microsoft has not set a timeline for full resolution and has not detailed what triggered the original misconfiguration in the authentication layer (Computerworld, yesterday). A fuller account of which regions and account types were affected, and why a routine authentication component ended up cascading across email, files, chat, and AI tools, has not yet surfaced.
Anyone still seeing errors should treat the admin center's service health page, not social feeds, as the definitive read on what's fixed and what isn't. Until Microsoft formally closes the incident, checking there beats guessing.
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