[Resolved] Mimecast: Microsoft Office 365 Service Degradation - January 22, 2026

Incident Status: Operational

Components:

United States Grid, United States B Grid, United States - Email Security, Cloud Integrated, United Kingdom Grid, United Kingdom - Email Security, Cloud Integrated, South African Grid, South Africa - Email Security, Cloud Integrated, Australian Grid, Australia - Email Security, Cloud Integrated, German Grid, Germany - Email Security, Cloud Integrated, Canadian Grid, Canada - Email Security, Cloud Integrated, Offshore Grid, Aware - US Azure East

Service:

Administration, Administration Console, Attachment Protect, Awareness Training, Aware - Search & Discover, Aware - Signal, Aware - Spotlight, CyberGraph, Email Processing, Impersonation Protect, POP3, Protection, Search, URL Protect, User Applications, Web Security

January 23, 2026 7:51AM UTC

RESOLVED

Microsoft has confirmed the resolution of the mail delivery issue affecting Office 365. We can also confirm that all Mimecast services are now operating normally. Accordingly, we are resolving and closing this incident. Thank you for your patience as we worked to resolve this incident.

January 23, 2026 3:07AM UTC

MONITORING

Mimecast has observed a decrease in mail queued for delivery to Office 365 hosts. While Microsoft has not yet issued a final all-clear, our global delivery queues are returning to, or have already returned to, baseline levels. We will continue to monitor Microsoft's incident for further updates. 

January 22, 2026 8:37PM UTC

MONITORING

Mimecast is aware of a service degradation affecting Microsoft Office 365. This issue is impacting mail delivery, directory synchronization, authentication services and others. Users may encounter delays in sending or receiving emails, difficulties with logging in, and problems accessing directory resources. Mimecast customers that have continuity features can consider scheduling a continuity event. Microsoft has acknowledged the situation and is actively working to resolve the issue as quickly as possible. status.cloud.microsoft/m365/referrer=serviceStatusRedirect