Microsoft 365 Down? What Your Business Should Do When Outlook and Teams Stop

When Microsoft 365 is down, first confirm it is Microsoft and not your own setup: check the official status page at status.cloud.microsoft, the Service health page in the Microsoft 365 admin center, and Microsoft's @MSFT365Status account on X. If Microsoft confirms an incident, there is nothing to fix on your side; switch the team to a backup channel, tell customers how to reach you, and check whether your website's emails are affected too.

The large outage on 12 November 2026, which took down Exchange Online mailboxes and disrupted Outlook, Teams and other Microsoft 365 services for many hours, is a good reminder that every cloud service fails sometimes. This guide covers how to check an outage properly, what usually keeps working, the website problem most businesses only discover during an outage, and a one-page plan so the next one costs you far less.

#What happened on 12 November 2026

On 12 November 2026, Microsoft reported that users were having trouble accessing Exchange Online mailboxes, first in the Americas. Two incidents were opened in the Microsoft 365 admin center: EX1550543 for Exchange Online and MO1550821 for Microsoft 365 more widely. Outlook was hit hardest, and Microsoft said Teams, SharePoint Online, Microsoft 365 Copilot and Defender XDR could also be disrupted, mainly the features that depend on Exchange Online.

According to SecurityWeek's reporting of Microsoft's updates, affected servers were failing automated health checks, a process that sets up secure connections was becoming overwhelmed, and Microsoft rolled back a recent network configuration change that coincided with the start of the problem. By the evening (US Eastern time), Microsoft said restarting affected servers was showing signs of improvement, but it had not yet confirmed full recovery or a root cause. Microsoft's service advisories reported no evidence of malicious activity.

Microsoft's own documentation says that for incidents with broad impact it publishes a preliminary post-incident review in Service health within 48 hours of resolution, and a final review within five business days. That review is the place to read the confirmed cause, rather than social media guesses.

#How to check whether Microsoft 365 is really down

Most "Outlook is down" moments are local: an expired password, a full mailbox, a broken Outlook profile or the office internet. A real outage looks different: many people in different places fail at the same time, on phones and computers alike.

Use the official sources, in this order:

1. The Service health page. If you are an admin, sign in at admin.microsoft.com and go to Health > Service health. Active incidents show with an ID, the affected services, a status (such as Investigating, Service degradation or Restoring service) and a feed of updates. Microsoft says it posts updates on incidents roughly every hour.
2. The public status page. If you cannot even sign in to the admin center, Microsoft points to status.cloud.microsoft for known issues.
3. @MSFT365Status on X. Microsoft posts updates on large events there.
4. Ask a colleague on another network. If their Outlook fails too, it is not your connection.

Sites like Downdetector show how many people are reporting a problem, which helps confirm it is widespread, but they cannot tell you the cause or when it will be fixed. Only Microsoft can.

#What to do (and not do) during the outage

Once Microsoft confirms an incident, the fix is on its side. Your job is to keep the business running and avoid creating new problems.

Do:

• Move internal chat to your backup channel (WhatsApp, phone or another tool) and tell the team where updates will be posted.
• Tell customers how to reach you. A short line on your website, social profiles and WhatsApp status ("Our email is affected by a Microsoft outage; call or WhatsApp us on ...") stops them thinking you have gone quiet.
• Keep working offline. Outlook keeps a local copy of recent mail, and Word and Excel files saved on your computer still open.
• Write down anything urgent that arrives by phone, so nothing is lost when email returns.
• Turn on Service health email alerts (in the admin center, Service health > Customize > Email) so you hear about the next incident early.

Do not:

• Reset passwords, recreate Outlook profiles or reinstall Office. The problem is not on your computer, and you may end up with a broken setup after Microsoft recovers.
• Change your domain's MX or other DNS records to "move" email in a hurry. Mail is usually queued and delivered once service returns; a rushed DNS change can send it nowhere.
• Resend the same email again and again. Messages sent during the outage may arrive late, and customers then receive several copies.

#The problem most businesses miss: website emails

Many small business websites send their emails (contact form notices, order confirmations, password resets) through the company's Microsoft 365 mailbox, using SMTP on smtp.office365.com. It is convenient because the domain is already set up. During an outage it means your website quietly stops sending too.

The result is worse than a slow inbox. A visitor fills in your contact form, sees "Thank you", and their enquiry never reaches you. A customer pays and receives no order confirmation. Nobody knows anything is wrong until they complain.

The fix is to send website email through a separate transactional email service such as Amazon SES, Brevo or Postmark, using your own domain. Your team's mailboxes stay on Microsoft 365; the website's emails go out through a different path, with delivery logs so you can see every message. My guides to sending website email through Google Workspace or Microsoft 365 and the transactional email providers compared explain the options, and if WordPress forms already go missing, start with WordPress not sending emails.

#Would Google Workspace have been safer?

Not in a way you can count on. Every large provider has outages, Google included. Microsoft's own published uptime figures show how rare they are for a full quarter, and also that they do happen: it lists 99.526% for the first quarter of 2026, compared with 99.95% or better in most earlier quarters.

Switching provider after one bad day rarely pays off. Spreading the risk does: keep website email on a separate service, keep a backup of your mailboxes, and make sure your team can still talk and reach customers when one tool is down. If you are choosing a suite for other reasons, my Google Workspace vs Microsoft 365 comparison covers the real differences.

#A one-page plan for the next outage

Write this down once, share it with the team, and the next outage becomes a short interruption rather than a lost day.

backup channel everyone knows

1

status message ready to post

1

email paths: team mail and website mail

2

mailbox backup kept outside Microsoft

1

1. Backup channel. One agreed place for the team to talk when email and Teams are down, with everyone already in it.
2. Status message. A ready-made line for your website, social profiles and WhatsApp, so you can post it in a minute.
3. Separate website email. Website forms, orders and password resets sent through a transactional provider, not through staff mailboxes.
4. Mailbox backup. Microsoft keeps your mail available, but a separate backup protects you from accidental deletion, account problems and lockouts. See my website backup and disaster recovery plan for how to think about backups in general.
5. Monitoring. Alerts for your website and your form deliveries, so you hear about a problem before customers do. My overview of website monitoring tools covers the free options.
6. Who checks what. One person checks Service health and posts updates; one person watches the phone and WhatsApp.

#When to get help

Most of this plan takes an afternoon to set up properly. The parts where help pays off are moving website email to a transactional provider without breaking deliverability (SPF, DKIM and DMARC need to be right), setting up mailbox backups, and adding monitoring with alerts that reach the right person.

I set up business email on Microsoft 365 and Google Workspace, move website forms and order emails to a reliable SMTP or transactional service, and add monitoring and alerts and off-site backups. If your website's emails went missing during this outage, that is the first thing worth fixing.