Mimecast incident

Secure Messaging Login

Resolved after 5 hours 52 minutes, affecting United States Grid and United States B Grid and 1 more, on August 24, 2026.

monitoring Aug 24, 2026, 11:01 PM UTC

We have implemented mitigation steps to address authentication issues for external Secure Messaging users. We are no longer seeing errors and services are operating normally across grids. Our Engineering team will continue to closely monitor availability and performance to ensure ongoing stability.

Started
Aug 24, 2026, 06:25 PM UTC
Resolved
Aug 25, 2026, 12:18 AM UTC
Duration
5h 52m
Detected by Pingoru
Aug 24, 2026, 06:25 PM UTC

Affected components

United States GridUnited States B GridUnited Kingdom GridSouth African GridAustralian GridGerman GridCanadian GridOffshore GridOffshore Grid (Offshore Grid — Authentication)

Update timeline

  1. investigating Aug 24, 2026, 06:25 PM UTC

    We are aware that some customers may be having their external users experience login issues with Secure Messaging. We are currently investigating and will post updates here as they become available.

  2. investigating Aug 24, 2026, 08:17 PM UTC

    We are continuing to actively investigate login issues affecting some customers' external users with Secure Messaging. Our teams remain fully engaged in troubleshooting to identify the root cause, and we will post updates here as they become available.

  3. identified Aug 24, 2026, 10:55 PM UTC

    We have implemented mitigation steps to address authentication issues for external Secure Messaging users. We are seeing improvements across grids and are continuing to test and apply mitigations to the authentication service. We will provide further updates as they become available.

  4. monitoring Aug 24, 2026, 11:01 PM UTC

    We have implemented mitigation steps to address authentication issues for external Secure Messaging users. We are no longer seeing errors and services are operating normally across grids. Our Engineering team will continue to closely monitor availability and performance to ensure ongoing stability.

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