Microsoft Outlook outage disrupts services for over 11,000 users in North America

On 5 July 2026 Microsoft reported a large‑scale outage of its Microsoft 365 services, including Outlook and Teams, that generated more than 11 000 incident reports across North America. Users experienced calendar‑sharing failures that rendered invitations invisible, and some Outlook.com accounts could not share calendars at all. The disruption was traced to a server‑side traffic‑handling issue in the region; Microsoft rerouted traffic and restored functionality within hours.

The outage occurred just after the U.S. Cybersecurity and Infrastructure Security Agency’s deadline for patching a critical SharePoint Server vulnerability (CVE‑2026‑45659). On the same day a phishing‑as‑a‑service platform, ARToken, was observed targeting Microsoft 365 credentials, heightening security concerns for affected organizations.

Microsoft issued patches for related bugs, including a missing Copilot button in the Outlook Windows app and image‑display problems in emails. Users and administrators were urged to apply the SharePoint security update and review defenses against phishing attacks.