Microsoft outage: What went wrong and has it been fixed?

A global Microsoft outage has disrupted prescription services, school IT systems and government communications in Ireland, leaving users unable to access email and other online tools.

The problems began yesterday evening and continued into today. Microsoft said services were recovering by 2pm, although some users were still experiencing access problems and delays receiving emails.

The disruption mostly impacted Microsoft's email infrastructure, with knock-on effects for features in Teams, Copilot and other Microsoft 365 products.

So, what went wrong, which services have been affected and how widespread has the disruption been?

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How has Ireland been impacted?

The HSE said that Healthmail, which deals with prescriptions, was unavailable due to the outage.

It advised GPs and pharmacists to use plain paper prescriptions under the General Medical Services (GMS) scheme until the outage is resolved.

The HSE said that it was reviewing all its systems for any further issues and will engage with services and patients if there are any impacts.

Schools using Microsoft 365 for communication and submitting work also faced disruption, according to Paul Crone, director of the National Association of Principals and Deputy Principals.

He said the outage would have caused a "little bit of panic" this morning, causing some teachers to pivot with lesson plans and that the outage would have had a greater effect on post-primary than primary schools.

A number of government departments and agencies were affected by the outage, with email services being the main area impacted.

Meanwhile, the Road Safety Authority confirmed its email specific services were impacted.

The National Cyber Security Centre said preliminary investigations indicate that it is an engineering issue affecting email and other online services with no evidence of malicious activity.

However, it said that criminals and scam calls increase during these types of incidents, "so all should be cautious around unexpected calls and messages, especially those containing links".

What products have been affected?

The outage has disrupted Outlook email as well as Teams, Word, OneDrive and Microsoft's AI assistant Copilot.

Microsoft has not revealed how many users have been affected, but the issues appeared to be wide-reaching.

It is estimated that Microsoft 365 products have over 450 million users worldwide.

What went wrong?

Microsoft said that its servers were experiencing "elevated load" across multiple regions, which was likely contributing to the outage.

However, it said that the elevated load was not driven by an increase in traffic, but by a number of servers being unexpectedly unavailable, creating a strain on the remaining servers.

These servers became unavailable after they failed automated health checks, the company said.

Microsoft said these health checks may have been failed by servers due to a specific component that is responsible for processing server health.

The company said it had found no evidence of malicious activity.

Has the issue been fixed?

Microsoft said services were improving by 2pm today, with email queues significantly reduced and approaching normal levels.

However, some users could still experience intermittent access problems or delays receiving emails as recovery continued.

The update followed several unsuccessful attempts to restore services overnight. Microsoft said some recovery measures had not worked as expected, while servers it restarted became unresponsive again when traffic returned.

How much disruption has it caused worldwide?

Service outage website Downdetector said that it had received reports of Microsoft 365 outages from 74 countries within an hour.

However, the outage is likely to have affected a much greater number of countries.

In the UK, England's NHS activated contingency plans and reverted to "other IT systems or paper records" to maintain essential care and appointments.

Australia's spy agency and federal police were also impacted while immigration services in New Zealand paused the processing visa applications.

Several Indian airlines also reported their email support services were impacted.

AI companies Anthropic and OpenAI both reported issues with "Microsoft connectors", which allows their products to integrate with Microsoft services.

When and where did the outage start?

Reports of problems began appearing on Downdetector at around 5.30pm yesterday, initially concentrated in North and South America, with just some reports of outages in Ireland at the time.

Shortly before 6pm, Microsoft said that it was investigating reports of users "experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas".

Soon after that update, Microsoft confirmed the issue may affect Microsoft 365 users "in any region".

Throughout yesterday evening and into this morning, spikes could be seen on Downdetector in Microsoft 365 outages in regions across the world.

It is unclear whether the outage affected users across the world at different times or if a higher volume of reports of the outage aligned closely with working hours in the given countries.