After a morning without email, the natural question is whether this was a freak event or a habit. The fair answer needs dates and sources, so here they are.
The quick answer: large, headline-making Microsoft 365 outages are uncommon but not rare. In 2026 there have been at least two that made international news, in January and November, plus shorter incidents in between. Third-party trackers count far more, because they include every small advisory. The sensible conclusion for a business is to plan for a few hours without email once or twice a year, and be pleasantly surprised when it does not happen.
How often does Microsoft 365 go down?
It depends on what you count. The tracker IsDown lists 229 Microsoft 365 incidents since June 2023, 85 of them in the last 12 months. Most of those are small: one feature, one region, some users. They are counted from Microsoft's own service communications, and most never reach the news.
Outages that stop a large share of customers from reaching email for hours are a much shorter list.
Source: IsDown, Microsoft 365 outage history (a third-party tracker, not Microsoft).
What were the notable Microsoft 365 outages in 2026?
| Date (US time) | What was reported | Microsoft reference | Source |
|---|---|---|---|
| 22 to 23 January 2026 | Outlook, Microsoft Defender, Microsoft Purview and other services affected, mostly in North America. Microsoft confirmed the impact was resolved early on 23 January and described it as a service load issue during maintenance | MO1221364 | TechRadar |
| 6 March 2026 | Some users in North America unable to access multiple Microsoft 365 services, for about 3 hours | See Service health history | IsDown |
| 8 April 2026 | Issues accessing multiple services including Teams and Outlook, for about 1 hour | See Service health history | IsDown |
| 12 to 13 November 2026 | Exchange Online mailboxes unreachable through multiple connection methods, with other Microsoft 365 services affected, in any region. Not declared resolved at the time of writing | EX1550543, MO1550821 | Our timeline, with sources |
This is a short list of examples, not a complete record. Your organisation's own history is in the Microsoft 365 admin center under Health, Service health, Issue history.
What does an uptime percentage mean in hours?
Cloud services are usually described with an uptime percentage. This table is plain arithmetic on a 365-day year, not a statement of what any provider has committed to. For Microsoft's actual commitment, read its Service Level Agreement, which we link in our service credit guide.
| Uptime | Downtime that still fits, per year |
|---|---|
| 99% | About 87.6 hours |
| 99.9% | About 8.8 hours |
| 99.95% | About 4.4 hours |
| 99.99% | About 53 minutes |
The point of the table: a service can have a bad morning and still be within a very high percentage for the year. High uptime and "never down" are different promises.
Is Microsoft 365 unreliable?
We are not going to hand out a verdict. Two things are true at once. Email on Microsoft 365 works on the overwhelming majority of days, which is why an outage is news. And an outage of several hours does happen, which is why a business that depends on email should have a plan for it. Any online service can have incidents; the question for an SME is not which vendor never fails, but what you do in the hours when yours does.
Nobody writes a headline that says "Email worked again today". That is the good news hiding inside the bad news.
What should a Singapore SME plan for?
- A few hours without email, once or twice a year. Decide in advance how staff and customers reach each other. See email continuity for SMEs.
- Your own copy of your data. See backup is not disaster recovery and Microsoft 365 backup to a Synology NAS.
- Alerts. Turn on Service health email notifications. See how to check Microsoft 365 status.
- A record. Note incident IDs and times in case you raise it later. See how to complain to Microsoft.
Related products and solutions from SourceIT
A cloud outage is one kind of downtime. A continuity plan usually covers a few others that are entirely on your side of the wall. None of these prevents a Microsoft-side outage.
| Kind of downtime | What a plan usually includes | Look at |
|---|---|---|
| Cloud service unavailable, or data deleted | Your own backup copy | Synology backup and data protection for business, Synology DS925+, or the QNAP NAS range |
| Power cut or power dip at the office | A UPS for the NAS, router and switch | APC Back-UPS series or the wider APC UPS range |
| Office network or security problem | A business firewall | Fortinet FortiGate firewalls for small businesses |
| Plan or licence questions | Knowing what your subscription includes | Microsoft 365 for Business plans |
Getting help in Singapore
For backup and continuity planning, call (65) 6978 3502, email Sales@sourceit.com.sg or use our contact page.
Frequently asked questions
How often does Microsoft 365 go down? Large outages that make the news are uncommon. In 2026 there were widely reported ones in January and November, with shorter incidents in between. Trackers that count every small advisory list many more.
When was the last big Microsoft outage before November 2026? A widely reported Microsoft 365 outage occurred on 22 to 23 January 2026, tracked by Microsoft as MO1221364.
Where can I see my own organisation's outage history? In the Microsoft 365 admin center under Health, Service health, Issue history.
This article is general information compiled from the sources linked above as at 13 November 2026. It is not a complete record of incidents and is not a statement by or on behalf of Microsoft. Microsoft, Microsoft 365 and Outlook are trademarks of the Microsoft group of companies.
