Microsoft addresses Outlook email problems

• Users encountered '451 4.3.2 temporary server issue' error messages, with Microsoft identifying that a portion of service infrastructure in North America was not handling traffic correctly
• The disruption also impacted searches in OneDrive cloud storage and other Microsoft services during peak business hours
• This follows a previous 21-hour Outlook outage that occurred in July, highlighting recurring reliability concerns with the widely-used email platform

Summary: Microsoft Addresses Outlook Email Problems

Key Issue:

Microsoft experienced technical problems with Outlook on Thursday during U.S. business hours, preventing users from sending and receiving emails. The outage affected schools, government institutions, and companies, prompting widespread complaints on social media.

Technical Details:

• At 2:37 p.m. ET, Microsoft acknowledged the issue via X (formerly Twitter)
• Users received "451 4.3.2 temporary server issue" error messages
• By 3:17 p.m. ET, Microsoft identified that "a portion of service infrastructure in North America" was incorrectly handling traffic
• The outage also impacted OneDrive cloud storage searches and other Microsoft services

Company and Products Affected:

• Microsoft (MSFT) - Primary company
• Outlook - Core email service within Microsoft 365 productivity software bundles
• OneDrive - Cloud file storage application also experienced disruptions

Historical Context:

Last July, Outlook experienced a more severe outage lasting 21 hours, indicating recurring infrastructure challenges.

Market Implications:

The mid-day outage highlights Microsoft's ongoing reliability challenges with critical business infrastructure services. As Outlook represents a core component of Microsoft 365—a major revenue driver—repeated outages could raise concerns among enterprise customers about service dependability. The incident occurred during peak business hours, maximizing disruption and potentially impacting Microsoft's reputation in the competitive cloud productivity market. Investor attention may focus on whether these technical issues reflect deeper infrastructure problems requiring significant capital investment.

The quick acknowledgment and response suggest Microsoft is prioritizing service restoration, though the frequency of outages may warrant scrutiny from investors and enterprise clients.