Microsoft 365 Down: What to Do While Outlook Is Out

If Outlook has been spinning on "Trying to connect" since last night, or Teams won't load your calendar, it isn't your PC. Microsoft 365 has been down or badly degraded for well over half a day, and as I write this (around 12:30 PM IST on Friday, November 13) Microsoft's own service health page still lists it as degraded for business and consumer accounts.

What happened

The trouble started on Thursday, November 12, US time. Microsoft is tracking it as two incidents: EX1550543 for Exchange Online (that's the mail and calendar backend) and MO1550821 for the wider Microsoft 365 suite. The Exchange incident says people may not be able to reach their mailboxes through Outlook on the web, the Outlook desktop app, phone mail apps that use Exchange ActiveSync, or apps that use Microsoft's REST connection. You can see the full wording in the University of Pennsylvania's public copy of Microsoft's incident reports.

The damage goes past email. According to Android Authority, which quotes Microsoft's status page, OneDrive, OneNote, Microsoft To Do, Teams and Microsoft 365 on the web are also hit. Gadgets 360 reported failed logins and mail that never arrived for users in India, and the University of Queensland's status page lists SharePoint, Copilot, Planner, Intune and Power BI among the services its staff lost.

The Microsoft 365 Status account on X has been posting updates all night. Its early posts blamed servers failing automated health checks. Later it said a core process on the affected servers was getting overwhelmed, and that servers it brought back could go unresponsive again once traffic hit them. Its latest post at 10:06 AM IST says Microsoft is throttling and redirecting traffic and is seeing "partial recovery" in the regions where it has done that. Microsoft executive Charles Lamanna said on X that there's no sign this was a cyberattack.

Why it matters

For a lot of companies, schools and colleges, Microsoft 365 is the whole office: mail, calendar, files and chat. When it falls over on a Friday, meetings get missed, invoices don't go out and shared files are stuck. Microsoft hasn't given an ETA. The University of Queensland, relaying what Microsoft told it, says mail that's been queued is expected to be delivered, just late. That's good news, but it also means a flood of delayed mail may land all at once when things recover.

What to do right now

1. Check before you troubleshoot. Open status.cloud.microsoft. If you're an IT admin, the Service health page in the Microsoft 365 admin center has more detail under EX1550543 and MO1550821.
2. Don't "fix" your PC. Don't remove and re-add your account, rebuild your Outlook profile, reset your password or reinstall Office. This is a server problem, and those steps can leave you with an empty mailbox that has to download everything again later.
3. Use what you already have. The Outlook desktop app in cached mode keeps a local copy of your mail, so you can usually still read and search older messages offline. Files you've synced with OneDrive on your PC are on your disk too.
4. Don't keep hitting Send. If a message is sitting in your Outbox, leave it. Sending it five times means five copies once the queue clears. For anything urgent, phone the person or use another channel.
5. Watch out for fake "verify your account" mail. Big outages bring phishing that pretends to be Microsoft asking you to log in again. Microsoft won't email you a sign-in link to fix this.
6. Check again once it's back. When Outlook reconnects, look at your Outbox and Sent folders and confirm that important mail actually went out.

My take

The people hit hardest here are office workers, students and small businesses on Microsoft 365 Business or school accounts. In India, where the outage ran straight into the Friday workday, that covers a big share of IT services companies and colleges. If you only use a personal Outlook.com or Hotmail address, you may be fine or only partly affected. Microsoft's status page does show consumer products as degraded too, so check it before you assume anything.

The thing I'd stress is to resist the urge to tinker. Every big outage produces the same advice threads: clear the credential cache, delete the profile, reinstall. None of that helps when the servers you're trying to reach are the ones having problems, and some of it creates extra work afterwards. Leave Outlook open, let it retry on its own, and get on with work that doesn't need it.

If you run IT for a small team, this is a good moment to write down a backup plan. Know where your team chats when Teams is down, keep a phone list somewhere other than Outlook, and make sure important files are synced locally, not just in the browser. The same goes for families on Microsoft 365. I covered the new 2TB shared storage plan recently, and today shows why the files you care about most should also live somewhere besides the cloud.

One thing to avoid mixing up: if your mail is bouncing with a 550 5.7.1 error that mentions SPF, DKIM or DMARC, that's a different problem. I explained that one in my post on Outlook.com bouncing mail without DMARC records. Today's outage shows up as connection errors, endless loading and mail that never arrives, not as bounce messages.

And if your Windows PC also feels sluggish while Outlook keeps trying to reconnect, check Task Manager before you blame the outage. My guide to fixing 100% disk usage on Windows 11 covers the usual causes.

I'll keep an eye on Microsoft's updates. Once the company publishes its post-incident report, the real cause should be clearer. Until then, be patient, don't hit Send twice, and don't click any "re-verify" links.