Microsoft confirms Exchange outage that affected users globally is now fixed

A laptop on a table with the Microsoft Exchange logo displayed
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Microsoft has confirmed that an outage in Outlook and Exchange Online that was affecting scores of users globally has now been fixed.

The company said a portion of its network infrastructure “was performing below acceptable thresholds” and re-routed affected connections to better-performing infrastructure to resolve the issue.

It later clarified that the root cause was a malfunctioning network router, and said most affected users were based in the North East of the US, though users online reported issues outside of North America, in regions such as Brazil and as far as Europe in Portugal.

IT admins are advised to check EX401976 and OL401977 in their admin centres for more details on the incident if required.

The issues with the core business services persisted for hours, according to user reports, and saw them unable to connect Outlook to Microsoft Exchange Online - Microsoft’s mail server - as well as experiencing degraded performance across the Outlook mobile app and outlook on the web.

Some users were still reporting issues after Microsoft announced that the issues had been resolved, following an internal investigation which lasted for around two hours.


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User complaints appeared to cease in the hours following Microsoft’s fix and some said that restarting Outlook resolved the remaining issues.

Outages affecting widely used technology services are relatively common and like Microsoft; latest, they are usually fixed quickly and not caused by any significant malfunction.

Microsoft suffered a separate outage last month which saw users struggling to connect to Exchange Online and multiple other Microsoft 365 services such as its collaboration app Teams.

It's rare that a company’s services, on which many business users rely, suffer outages that cause lasting impact. However, collaboration software giant Atlassian announced a cloud outage that it said would take more than two weeks to fix.

The owner of popular tools such as Trello said an outage in its Jira and Confluence products didn’t affect all customers but admitted the outage was “unacceptable”. The timing was also unfortunate, as customers began to report issues as it was hosting its flagship Team ‘22 conference where it usually announces new products.

Connor Jones

Connor Jones has been at the forefront of global cyber security news coverage for the past few years, breaking developments on major stories such as LockBit’s ransomware attack on Royal Mail International, and many others. He has also made sporadic appearances on the ITPro Podcast discussing topics from home desk setups all the way to hacking systems using prosthetic limbs. He has a master’s degree in Magazine Journalism from the University of Sheffield, and has previously written for the likes of Red Bull Esports and UNILAD tech during his career that started in 2015.