Massive Microsoft 365 outage causes auth issues, service failures
Massive Microsoft 365 outage causes auth issues, service failures
摘要: Massive Microsoft 365 outage causes auth issues, service failures
Sergiu Gatlan
August 31, 2026
12:56 PM
Microsoft is investigating a wides
正文
Massive Microsoft 365 outage causes auth issues, service failures
Sergiu Gatlan
August 31, 2026
12:56 PM
Microsoft is investigating a widespread service issue causing authentication issues, connection problems, service delays and failures, and various other issues for Microsoft 365 customers.
It first acknowledged this incident (tracked under
EX1464935
in the admin center) at 5:30 PM UTC, when it began investigating a stream of
social media
regarding multiple issues affecting Exchange Online.
However, while Exchange Online is the most impacted service, Microsoft revealed in a new incident report (
MO1465074
) that this outage also impacts multiple other Microsoft 365 services, including OneDrive for Business and SharePoint Online, Microsoft Teams, Microsoft Purview, and Microsoft Defender XDR.
According to outage tracking service Downdetector, tens of thousands of
Microsoft 365
users are affected and experiencing issues receiving emails via Outlook and accessing Microsoft cloud services.
Microsoft says the list of Exchange Online symptoms includes:
Delays or failures when sending or receiving email messages.
Delays, failures, or incomplete results when searching for content within Exchange Online mailboxes.
Authentication-related errors when accessing Exchange Online services.
Difficulties accessing or performing actions within Exchange administration experiences.
Intermittent failures affecting mailbox operations and message delivery workflows.
Although the company has yet to reveal which regions are impacted, it has classified this outage as an incident, which is typically used to describe critical service issues with noticeable user impact.
"We've isolated a common failure pattern across affected Exchange Online requests that is associated with authentication and protocol connectivity," Microsoft added in the latest admin center update.
"We're analyzing service telemetry to identify the under