Outlook went down for two workdays. Here is how it affects your business

On Thursday, 12 November 2026, Microsoft Outlook stopped working for people around the world. It started around 16:00 GMT, which is 18:00 in Windhoek and Johannesburg, and it was still not fully fixed when offices opened on Friday morning. Exchange Online, Teams, SharePoint and Copilot were hit too. Within an hour, Downdetector had problem reports from 74 countries.

For a lot of businesses in your country, Outlook is not just an app. It is where quotes go out, where orders come in, where the bank sends payment confirmations and where tender clarifications arrive. When it goes quiet for most of two working days, the whole business slows down with it.

What actually happened

Microsoft says this was not a hack. In its own words it was "a technical issue not related to cyber or AI". A network change exposed a problem left behind by an earlier capacity upgrade. Connection requests started queuing up until the affected servers ran out of capacity, and the web, desktop and mobile versions of Outlook could not connect.

Engineers rolled back the change and rebuilt the affected servers, then let traffic back in slowly. That is why service came back in waves, and why some people saw it working, then failing again, on Friday morning.

One good decision: Microsoft extended the email timeout window to 48 hours. That means most messages sent to you during the outage were held in a queue and delivered late, not thrown away.

How it affects your business

Big organisations noticed first. An airline in India warned customers it might not receive their emails. Government systems in Japan, and schools and courts in Australia, reported problems. But the businesses that feel an outage like this the most are small and medium companies, because they usually run everything through one mailbox and have no backup plan.

• Lost sales. A customer who asked for a quote on Thursday afternoon and heard nothing until Friday may have already gone to a competitor.
• Payments on hold. Proof of payment, remittance advice and invoice emails arrived late, so goods and services were held back while people waited.
• Missed deadlines. Tender submissions, clarification questions and supplier confirmations that depend on email had no way through.
• Locked accounts. Many systems send login codes and password resets by email. No email meant no way in.
• Meetings cancelled. Teams calls and calendar invites were part of the same outage.
• Staff time wasted. Every person who restarted their laptop, reset their password or called IT because they thought the problem was on their side.

What to do now

Outages at this scale happen every year or so. Microsoft 365 was down across North America for almost 10 hours in January this year. Here is what we recommend to every client:

• Check the backlog. Go through mail received from Thursday afternoon onwards. Some messages arrived hours late and are sitting below newer ones.
• Resend anything important. If you sent a quote, invoice or submission during the outage and have no reply, send it again or call to confirm it arrived.
• Have a second channel ready. A WhatsApp Business number or a phone line that customers already know about means a bad day, not a lost day.
• Send system emails through a separate route. Invoices, receipts and website form messages do not need to depend on the same service as your staff inboxes. A separate sending service keeps them flowing.
• Bookmark the status page. Microsoft posts updates on its Microsoft 365 service health page and on the @MSFT365Status account on X. Checking there first saves a lot of time.
• Write a one-page plan. Who tells customers, which channel you switch to, and who checks the backlog afterwards.

Whether you use Microsoft 365, Google Workspace or your own mail server, the goal is the same: one outage at one company should not stop your business from talking to customers. Make sure your mail passes the basic checks as well. Our guide on why business emails land in spam covers the three DNS records every domain needs.

If you want a backup email route, a status alert for your team or a simple outage plan for your business, talk to us. We set up business email and keep it running for companies every day.