Microsoft issue update as major outage causes global disruption

Outlook emails could face delays for up to 48 hours

The company said the problem began after several of its servers became "unexpectedly unavailable". 

This pushed extra traffic onto the remaining systems, putting them under pressure and affecting access to its services.

Microsoft has described the cause as "elevated load" on its infrastructure, meaning its servers were dealing with more demand than they could handle. It has not attributed the incident to a cyber attack.

The scale of the disruption was reflected in reports to Downdetector, which recorded almost 140,000 complaints about Outlook at around 6pm GMT on Thursday.

Initial attempts to restore normal service did not go as planned, with Microsoft saying its fixes were "not taking as expected". 

By Friday morning, however, the company said it had seen "marginal success" in its recovery work.

Now, in a new update, Microsoft says it is still working to bring its affected 365 services back online, with repairs being rolled out gradually across its infrastructure.

The company has detected some progress, but warned that services are still experiencing inconsistent performance and system capacity has yet to return to normal.

“To protect delayed mail, we’ve extended the email timeout window to 48 hours while queue and backlog processing continues.”