SINGAPORE – Microsoft Outlook has been mostly restored to its full operationality, after an outage on Tuesday left users unable to send or receive e-mails.

In its latest update issued at 11pm, Microsoft said service availability was now at 99.9 per cent, with the majority of the impact being “remediated”.

The tech giant added that it would continue to monitor the situation and had begun to perform targeted resets on back-end mailbox components to ensure that the service would be up and running for all users.

According to outage tracking website downdetector.com, problems with the service were first detected at around 12pm in Singapore.

It is currently unclear how many users are affected, although many have taken to social media to highlight their inability to send and receive e-mails through the service.

On its website, Microsoft said it was investigating a potential issue, with reports of problems accessing Outlook.com.

It said it had identified a recent change that “may be causing issues with send, receive, or e-mail search”, and was working to restore access to the service.

As at 1.26pm, the tech giant said the issue mainly affected users located in the North American region.

In an update at 3pm, Microsoft said those in other regions may also be impacted, due to affected infrastructure in North America.

The outage also affected other functions, such as the calendar used by Microsoft Teams, it added.

However, there has been gradual improvement for these users, and the company is carrying out targeted operations to restore service.

The latest outage comes after a similar one on Jan 25, when users found themselves unable to access several Microsoft 365 services – with many of the affected apps being an integral part of operations for schools and businesses.