Mimecast experienced a minor incident on September 4, 2026 affecting United States Grid and United States B Grid and 1 more component, lasting 4h 55m. The incident has been resolved; the full update timeline is below.
Affected components
United States GridUnited States B GridUnited Kingdom GridSouth African GridAustralian GridGerman GridCanadian GridOffshore GridOffshore Grid (Offshore Grid — Email Processing)
Update timeline
- monitoring Sep 04, 2026, 10:55 AM UTC
We are aware that some customers may be experiencing email delays, with some seeing an increased volume of emails on their delivery queue. Our investigation shows that this issue is impacting emails to Office 365, coinciding with an incident reported by Office 365 on their end. We will continue monitoring and will post updates here as they become available.