Microsoft Outlook Users Face Widespread Disruptions in North American Infrastructure Failure

Thousands of Microsoft Outlook users lost access to email and related services on Jan. 22, 2026, when a major outage struck Microsoft 365 applications across North America.

The problems started around 2:30 p.m. ET and persisted for more than nine hours, with reports peaking at over 15,000 on outage tracking site Downdetector.

Affected components included Outlook for sending and receiving messages, Microsoft Teams for collaboration, Defender for security functions, and Purview for compliance tools.

Exchange Online, the backend platform handling enterprise email, calendars, and contacts, accounted for 66% of user complaints.

Microsoft engineers redirected traffic to backup systems while addressing the core issue in its North American data centers.

The company attributed the failure to reduced capacity during routine maintenance, which led to elevated service loads overwhelming the infrastructure.

"We’ve identified a portion of service infrastructure in North America that is not processing traffic as expected," Microsoft posted on X at 3:23 p.m. ET.

By 1:30 a.m. ET on Jan. 23, services stabilized for most users, with reports dropping to under 2,000.

"Impact has been resolved," Microsoft announced on X.

The incident followed a shorter disruption on Jan. 21, which Microsoft linked to a third-party internet service provider connection problem.

As of Jan. 23 afternoon, Downdetector logged ongoing complaints from Outlook users about delayed message delivery and login failures.