Microsoft Outlook and Exchange Outage severely affect users across the country.

The Microsoft Outlook/Exchange outage (tracked internally by Microsoft as EX1464935) is a major, ongoing authentication‑related failure affecting Exchange Online, the cloud backend that powers Outlook for Microsoft 365 users. This is a widespread, multi‑hour outage impacting sending, receiving, searching, and even logging into mailboxes.

What’s actually broken
Microsoft has confirmed that the root cause is an authentication component failure inside Exchange Online. This outage is preventing normal mailbox operations and causing cascading issues across other Microsoft 365 services.

Users are currently experiencing:

• Delays or failures sending and receiving email
• Authentication errors when trying to sign in
• Missing or delayed search results in mailboxes
• Intermittent failures performing mailbox actions (moving mail, opening folders, etc.)
• Problems accessing Outlook on the web and the Outlook app

Downdetector reports peaked at 5,000–6,000+ outage reports, indicating a large-scale disruption across the U.S.

Timeline

• Monday, August 31, 2026  @ 8:00 a.m. PT (11 a.m. ET) we saw the first major spike in outage reports
• Late morning–afternoon — Microsoft confirms an authentication component is failing
• Afternoon–evening — Microsoft begins testing a remediation strategy on part of the infrastructure
• As of 8:00PM Monday evening, as we put this information together, recovery is partial and ongoing, with no published ETA for full resolution

 Microsoft’s current status
Microsoft engineers are:

• Re‑applying core authentication components across affected environments
• Expanding mitigation across the infrastructure
• Monitoring downstream recovery (mail flow, search, mailbox operations)

They have also confirmed the issue is spilling over into other Microsoft 365 services, not just Exchange Online.

Scope of impact
This outage affects:

• Outlook desktop
• Outlook mobile
• Outlook on the web
• Any Microsoft 365 tenant relying on Exchange Online
• Admin center Exchange tools

It is not limited to a single region — reports span the entire U.S. and beyond.

What you can do right now
While Microsoft works on remediation:

• Avoid password resets or MFA changes until authentication stabilizes
• Try Outlook mobile — some users report slightly better connectivity
• Retry mailbox actions periodically as recovery is rolling out gradually
• Monitor Microsoft 365 Status (@MSFT365Status) for real‑time updates 

Thanks to TechCrunch
https://techcrunch.com/2026/08/31/microsoft-tests-fix-for-latest-hours-long-outlook-outage/