Australia's cybersecurity chief investigating Microsoft outage

Australians are reporting problems accessing Microsoft's email and other online services, as the national cyber security coordinator looks into the outage.

Businesses, government agencies and other organisations have been brought to a standstill as they wait to regain access to their email and other connected systems.

Microsoft said users could have trouble connecting to several of its Microsoft 365 services, including Exchange Online, Teams and SharePoint.

"We are aware and investigating reports of users experiencing issues with Microsoft 365 services, primarily issues with Exchange Online," a Microsoft spokesperson told the ABC.

Online outage reporting service Downdetector Australia recorded more than 4,400 reports of problems with Outlook by 8:20am on Friday.

A spokesperson for the home affairs minister said the National Cyber Security Coordinator, Lieutenant General Michelle McGuinness, was aware of the outage and looking into it.

An update from Microsoft said some servers had become unresponsive and may involve a component that's supposed to check whether their services are healthy.

It said the company is investigating recent configuration changes as possible contributors to the problem.

Some Microsoft users said the Outlook problems was also restricting access to other services because they were unable to utilise two-factor authentication codes to log in.

Growing reliance on cloud service providers an issue

University of Melbourne associate professor Adel Toosi said the widespread disruption was the downside of a growing reliance on a handful of major cloud service providers.

Professor Toosi said centralising services by using cloud computing providers like Microsoft was often cheaper because of the economies of scale, but also meant there was less redundancy if an error occurred.

While major providers typically distribute data across multiple geographical locations, Professor Toosi said they were still vulnerable to underlying flaws in the company's systems.

Microsoft said it had tested an alternative way to check the health of some affected servers, allowing those machines to return to service.

It was applying the change more broadly and preparing an automated process to detect and restart servers that stopped responding.

In an update issued at 8:41am AEDT, the company said it was continuing to restart and check affected servers before returning them to service