On Thursday, November 12, 2026, a widespread Microsoft 365 outage left businesses around the world unable to reach Outlook email, and it wasn't just email. Microsoft listed Exchange Online, Microsoft Teams, SharePoint Online, Microsoft 365 Copilot and Microsoft Defender XDR as affected, and users also reported problems with OneDrive and Office on the web. Microsoft said the outage could affect Microsoft 365 connectivity "for users in any region." At its peak, Downdetector logged roughly 130,000 Outlook problem reports. Microsoft traced the problem to a large number of servers failing health checks and dropping out of service, which overloaded the servers that were left. As of about 4 p.m. Eastern, Microsoft's public status page still showed the service as degraded.
This post reflects what Microsoft and news outlets reported as of the afternoon of November 12. We'll update it if Microsoft publishes a final cause.
What went down
According to Microsoft's status updates and live coverage from Tom's Guide and Windows Central:
| Service | What people saw |
|---|---|
| Outlook / Exchange Online | Couldn't connect, send or receive work email, in desktop Outlook, on the web and on phones |
| Microsoft Teams | Chats, calls and meetings failing to connect |
| SharePoint Online and OneDrive | Shared files and documents unavailable for many users |
| Microsoft 365 Copilot | Unavailable along with the services it relies on |
| Office on the web | Word, Excel and PowerPoint online failing to load for some users |
| Microsoft Defender XDR | Listed by Microsoft as affected |
| Microsoft 365 admin center | Hard to reach, so Microsoft posted updates on its public status page and its Microsoft 365 Status account on X instead |
The incident is tracked as EX1550543 and MO1550821 in the Microsoft 365 admin center, if your IT person wants the official record.
Not everyone was affected equally. Windows Central reported "mixed results" in its own testing, and some users kept working through the outage while others were locked out completely.
What Microsoft said caused it
Microsoft's explanation changed over the afternoon as its engineers dug in. In order:
- Elevated load. Microsoft first said "a portion of infrastructure is experiencing elevated load across multiple regions," and began redistributing connection traffic across its worldwide infrastructure.
- Not more traffic, fewer servers. It then said the load "isn't driven by an overall increase in traffic, but by a large number of servers being unexpectedly unavailable," shifting work onto the servers still running. Microsoft paused all deployments and configuration changes while it reviewed recent changes.
- Failed health checks. Microsoft said the failures may come from a specific component on the affected servers that processes automated health checks. Servers that failed those checks were pulled out of service. It deployed a change to bypass that component on a subset of servers and restarted servers that had become unresponsive.
- Recovery in progress. In its latest update reported by Tom's Guide, Microsoft said an alternative health check method had let a subset of servers return to service, that it was applying the change more broadly, and that it had identified "a small number of configuration updates" it was investigating as potential contributors.
In plain English: automated systems that are supposed to take sick servers out of rotation started pulling out healthy ones, and the rest couldn't carry the load.
Windows Central also noted reports of problems at Google, AWS, Steam and Cloudflare around the same time, though no connection had been confirmed. That matters for the next part of this post: no cloud provider is outage-proof.
What it cost small businesses
For a small business on Microsoft 365, an outage like this doesn't just stop email. When Outlook, Teams and SharePoint go down together:
- Customers can't reach you, and you can't tell them why
- Quotes, invoices and orders sitting in inboxes stall
- Calendar invites and meeting links fail
- Shared files your team needs are out of reach
- Automations that watch an inbox or a SharePoint folder stop running (see our guide to automating quote requests)
The common thread is that everything lives with one provider. That's convenient on a normal day, and it's why one bad day hits so hard.
What to do today
If your business is still affected:
- Check the source. Use Microsoft's status page, not social media guesses. Don't reset passwords or reinstall Outlook; the problem isn't on your end.
- Tell customers another way. A short note on your website, a social post, or a pinned message saying email is delayed and giving a phone number goes a long way.
- Use a backup channel for your team. A group text or phone tree works fine for a few hours.
- Expect a backlog. When service returns, mail that was delayed may arrive in a rush. Watch for anything time-sensitive and for bounce-backs your customers may have received.
- Watch for phishing. Big outages bring fake "Microsoft account" emails and texts. Don't sign in through links you didn't go looking for.
Should you move to Google Workspace?
For some businesses, yes. Google Workspace gives you Gmail, Calendar, Drive, Docs, Sheets and Meet in one subscription, and many small teams find it simpler to manage than Microsoft 365. If you were already frustrated with Outlook, Teams or SharePoint before today, this outage is a good reason to finally look at it.
But be honest about the reason. Google has outages too, and any single provider can have a bad day. Moving is worth it when Google Workspace fits how your team works better, not just because Microsoft went down once. Here's how we'd weigh it:
Google Workspace tends to fit well when:
- Your team mostly uses email, calendar, shared documents and video calls
- People work in the browser and on phones more than in desktop Office apps
- You want simpler sharing and real-time collaboration on documents
- Nobody in-house enjoys administering Microsoft 365
Staying on Microsoft 365 may make more sense when:
- Your work depends on advanced Excel, Access or Office add-ins
- Line-of-business software is built around Outlook or Teams
- You rely heavily on Microsoft-specific security, device management or compliance features
- You've invested in SharePoint sites and workflows that would need rebuilding
Either way, the lesson from today applies: know what you'd do if email were down for a day, keep a way to reach customers that doesn't depend on it, and make sure someone owns your accounts, domain and DNS.
What a migration to Google Workspace involves
Moving from Microsoft 365 to Google Workspace is very doable, but it isn't just flipping a switch. A typical migration covers:
- Planning. Listing every user, shared mailbox, distribution list, shared calendar and file location, and deciding what moves and what gets cleaned up.
- Setting up Google Workspace with your domain, users, groups and security settings, like two-step verification.
- Moving email, calendars and contacts. Google's data migration service can copy email, calendar and contact data from Exchange Online, and it doesn't delete or change anything in Microsoft 365, so you can migrate while staying live. Google notes that not every Exchange Online feature carries over, which is why planning matters.
- Moving files from OneDrive and SharePoint into Google Drive and shared drives, keeping folder structure and sharing permissions sensible.
- Switching mail delivery. Updating your domain's DNS records (MX, SPF, DKIM and DMARC) at the right moment so mail starts arriving in Gmail without losing messages or landing in spam.
- Reconnecting everything else. Website contact forms, scanners, CRMs, accounting tools and automations that send or read email all need to point at the new system.
- Training and cutover support so your team knows where everything is on day one.
Most of the risk is in steps 5 and 6: mail that gets lost during the DNS switch, and the forgotten contact form or automation that quietly stops working.
How Prodjex helps
Prodjex is a Kansas City area software and automation company, and we migrate businesses from Microsoft 365 to Google Workspace. We plan the move, set up Workspace, migrate email, calendars, contacts and files, handle the DNS cutover, and reconnect your website forms and automations so nothing falls through the cracks. If moving isn't the right call for you, we'll say so and help you put a simple continuity plan in place instead.
After the move, our AI automation service can connect Google Workspace to the rest of your tools, and our care plans keep your website and integrations monitored.
Book a free call and tell us what your team runs on today. We'll tell you honestly whether moving to Google Workspace makes sense, and what it would take.