Microsoft 365 and Outlook are down for many – here’s everything we know about issues affecting the apps, as a disruption is confirmed

Here’s what Microsoft’s status page says is impacted

As well as Microsoft’s post on X, the status page – which I’ve finally got loading again – does a good job of setting the scene and showing where we are with this ongoing disruption.

I’ll copy it in full below, but the gist is that inbound and outbound mail through Exchange Online and Outlook are both impacted. There’s a chance you’ll encounter this specific error message as well: “451 4.3.2 temporary server issue”. Using the search functionality in OneDrive and SharePoint Online may fail, as well as accessing Microsoft Purview, Microsoft Defender XDR, and the Microsoft 365 admin center may not load.

So yes, it does match the comments folks are leaving on Down Detector, and Microsoft says the cause is that a “portion of dependent service infrastructure in the North America region isn’t processing traffic as expected.” This service disruption for Microsoft 365 and Outlook is mostly impacting North America as well.

“More info: More info: Users may be receiving a “451 4.3.2 temporary server issue” error message when attempting to send or receive email through Outlook.

Some of the impacted service functions include, but may not be limited to:

– Sending and receiving email through Exchange Online, including notification emails from Microsoft Viva Engage.

– Collecting message traces may be delayed or fail.

– Searches within SharePoint Online and/or Microsoft OneDrive mail be delayed or fail to complete.

– Accessing the service portals, including Microsoft Purview, Microsoft Defender XDR, and the Microsoft 365 admin center.

Current status: We’re continuing to review what actions are required to restore the affected infrastructure to a heathy state and rebalance the service traffic to achieve recovery.

Scope of impact: Any users served through an affected section of service infrastructure in the North America region may be intermittently impacted.

Root cause: A portion of dependent service infrastructure in the North America region isn’t processing traffic as expected.

Next update by: Thursday, January 22, 2026, at 11:00 PM UTC”

Let’s take a count of where things currently stand – while I was able to load Microsoft’s own status page, which confirmed an active disruption with Microsoft 365, I’m having some difficulty loading it at the moment.