A Microsoft Outlook outage that began around 1pm ET on Thursday disrupted email, calendar, video conferencing and cloud storage systems used by companies, schools and local governments across the United States. By Friday morning, Outlook had started to resume normal operations, though Microsoft noted that some users may still experience intermittent access issues or delayed email delivery as recovery continued.
The disruption cascaded across public services. In Colorado, an Arapahoe county detention facility said it could not process online bond payments to release detainees, requiring residents to pay in person at the jail. Emergency management services in Fredericksburg and Gillespie county in Texas were unable to receive emails and asked residents to call instead. The Washington suburban sanitary commission, which provides drinking water and sewer treatment to parts of Maryland, said technicians may be delayed and some customers had trouble paying water bills. The Los Angeles county sheriff's department reported disruptions in email and communications platforms.
School districts in Richmond, Virginia, and Port Washington, New York, told parents to reach out by phone or through other online educational platforms, though the Albany school district said it had restored services. The Colorado School of Mines encouraged faculty to be flexible with assignment deadlines for students unable to access Microsoft tools. In Washington DC, congressional staff complained that the outage disrupted negotiations on pending legislation during the lame duck session of Congress, with one communications director questioning whether officials should conduct business via direct message instead.
Microsoft executive Charles Lamanna said late Thursday that there was no indication the outage resulted from malicious or cyber activity. OpenAI and Claude, developed by Anthropic, reported they were investigating issues with Microsoft connectors that degraded performance. On Wall Street, Workhorse Group rescheduled its third-quarter earnings call that had been scheduled for Thursday afternoon.
For businesses and government agencies relying on Microsoft services, the outage demonstrated the vulnerability of depending on a single provider for critical communications and administrative functions, leaving them unable to process payments, communicate with the public, or conduct routine operations.