Mimecast Outage History
Daily status observations, past incidents, and reported issue history for Mimecast.
Checking current status...
90-Day Trend
Monthly Status Summary
| Month | Issue-free days | Days Tracked | Days with Issues |
|---|---|---|---|
| August 2026 | 92% | 25 | 2 |
| July 2026 | 61.3% | 31 | 12 |
| June 2026 | 70% | 30 | 9 |
| May 2026 | 100% | 5 | 0 |
This percentage summarizes normalized provider-status observations by calendar day. It is not duration-based, component-weighted, or contractual uptime. See the methodology and limitations.
Daily Status (Last 91 Days)
May 27
Today
Operational
Degraded
Partial Outage
Major Outage
Maintenance
No Data
Incident History
August 2026
Secure Messaging Login
Started:
Authentication
United States Grid
United States B Grid
United Kingdom Grid
South African Grid
Australian Grid
German Grid
Canadian Grid
Offshore Grid
investigating
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.
monitoring
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.
monitoring
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.
monitoring
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.
Degraded Service – Administration Console Authentication issue
Started:
Administration Console
United States Grid
United States B Grid
United Kingdom Grid
South African Grid
Australian Grid
German Grid
Canadian Grid
investigating
We have taken mitigation steps and believe we have resolved the issue causing login failures and disruption to Administration Console for some customers across multiple regions. Our Engineering team is closely monitoring the situation as services continue to stabilize and return to normal levels. We will provide further updates here.
monitoring
We have identified the cause of authentication issues affecting the Administration Console for some customers. Expect to see intermittent failures and high latency. Email flow and other services are not impacted. Our teams are actively working on a resolution, and further updates will be posted here as they become available.
monitoring
We have identified the cause of authentication issues affecting the Administration Console for some customers globally. Email flow and other services are not impacted. Our teams are actively working on a resolution, and further updates will be posted here as they become available.
Aware, Analysis and Response, Human Risk Command Center, Engage, and CyberGraph : Login/Access Issues (AU, CA)
Started:
Administration Console
Aware - Search & Discover
Australian Grid
Canadian Grid
investigating
We have implemented mitigation steps to address login and access issues for some customers hosted on our AU and CA grids, impacting Aware, Analysis and Response, Human Risk Command Center, Engage, and CyberGraph. We are no longer seeing errors and services are operating normally. Our Engineering team continues to closely monitor availability and performance to ensure ongoing stability.
monitoring
We have identified the cause of intermittent login and access issues affecting some customers hosted on our AU and CA grids, impacting Aware, Analysis and Response, Human Risk Command Center, Engage, and CyberGraph. Our teams are actively working on the resolution, and further updates will be posted here as they become available.
July 2026
Outbound delivery delays on AU grid
Started:
investigating
We have applied mitigation steps to resolve the issue causing outbound MX lookup errors for a subset of AU-hosted customers. Some outbound mail may still be delayed while the backlog clears. We're monitoring closely to confirm full recovery and will provide further updates as they become available.
monitoring
We have identified the issue causing outbound MX lookup errors for a subset of AU-hosted customers and are working on a resolution. We'll provide further updates as they become available.
monitoring
We are aware that some customers on our AU grid may be experiencing outbound mail delivery delays due to MX lookup errors, with messages held in the delivery queue. We are investigating and will post updates here as they become available.
Email Processing Delays: USB
Started:
investigating
We have implemented mitigation steps to address intermittent delivery delays for some customers hosted on our USB grid. Our processing queues are in a healthier state, and we are observing normal mail delivery operations.
Our Engineering teams will continue monitoring to ensure stability in our environment.
monitoring
We have implemented mitigation steps to address intermittent delivery delays for some customers hosted on our USB grid. Our teams are seeing improvements and are continuing to work toward full resolution.
We will provide further updates as they become available.
monitoring
We have identified the cause of the intermittent delivery delays affecting some customers hosted on our USB grid. Our teams are actively working on a resolution, and further updates will be posted here as they become available.
monitoring
We are aware that some customers hosted on our USB grid may be experiencing intermittent delivery delays. We are currently investigating and will post updates here as they become available.
Administration Console Page Loading Issue
Started:
investigating
We have taken mitigation steps and believe we have resolved the issue affecting some customers where attempting to load certain pages within the Mimecast Administration Console redirected users back to the Main Page.
Our Engineering team is closely monitoring the situation to ensure continued stability and performance. We will provide further updates here as they become available.
monitoring
Our Engineering teams are actively engaged implementing mitigation steps to resolve the issue affecting some customers, where attempting to load certain pages within the Mimecast Administration Console redirects back to the Main Page. We will continue to provide updates here as they become available.
monitoring
We continue to work on a resolution for the issue affecting some customers, where attempting to load certain pages within the Mimecast Administration Console redirects back to the Main Page. We will continue to provide updates here as they become available.
monitoring
We have identified the cause of the issue affecting the loading of certain pages within the Mimecast Administration Console. Our teams are working on implementing remediation to resolve the issue, and further updates will be posted here as they become available.
monitoring
We are aware that some customers may be experiencing an issue when attempting to load certain pages within the Mimecast Administration Console, resulting in a redirect back to the Main Page. We are currently investigating the issue and updates will be posted here as they become available.
Intermittent Processing Delays on AU Grid
Started:
investigating
Recovery is ongoing for the incident affecting some customers on our AU grid and we continue to see improvements. There may still be some delays in mail flow as the backlog clears. We are closely monitoring performance and will provide further updates as they become available.
monitoring
We have taken mitigation steps and continue to see improved mail processing performance for previously impacted customers hosted on our AU grid. We are continuing our resolution and further updates will be posted here.
monitoring
We are aware that some customers hosted on our AU grid may be experiencing intermittent delivery delays, with messages being held in the processing queue. We are currently investigating and will post updates here as they become available.
S&R Migration Failures
Started:
resolved
We are aware of a service disruption that is preventing customers from completing S&R migrations. We are currently investigating the issue and will post further updates here as they become available
Administration Console access issue- USB
Started:
investigating
We have implemented mitigation steps and believe we have resolved the intermittent issues affecting access to the Mimecast Administration Console for customers hosted on our USB grid. Our Engineering team is closely monitoring the situation to ensure a full resolution.
monitoring
We have identified the cause of the intermittent issues affecting customers hosted on our USB grids experiencing difficulty accessing the Mimecast Administration Console. Our Engineering team is actively working on implementing a fix and we will provide further updates as they become available.
monitoring
We are aware that some customers hosted on our USB grid may be experiencing intermittent issues accessing the Mimecast Administration Console. Our Engineering team is actively investigating the issue and we will provide further updates as they become available.
Degraded Outbound Email Processing on Multiple Grids
Started:
investigating
We have taken mitigation steps and believe we have solved the issue of our recent service disruption that impacted outbound email processing across all regions. The Engineering team will closely monitor as the error rates have returned to normal levels.
All services should now be functioning normally. We appreciate your patience while we worked to resolve this issue.
monitoring
We believe we have identified the issue affecting customers across multiple grids, where some outbound messages were delivered with a blank or "null" message body.
We have taken initial mitigation steps and are seeing error rate improvements in impacted regions. The Engineering team will continue the mitigation process while closely monitoring performance.
Customers may still experience intermittent issues while mitigation work continues. We will provide further updates here as they becom...
monitoring
We are aware of a service disruption impacting outbound email processing for some customers across multiple grids. Some outbound messages delivered to external recipients may contain a blank or "null" display in the body.
Our Engineering team is actively working to determine the root cause and scope of impact. Further updates will be posted here as they become available.
All other Mimecast services are operating as normal.
monitoring
We are aware of a service disruption impacting outbound email processing for some customers across multiple grids. Some outbound messages delivered to external recipients may contain a blank or incorrect message body.
Our Engineering team is actively investigating to mitigate the issue. Further updates will be posted here as they become available.
All other Mimecast services are operating as normal.
Australia Region: Email processing delays
Started:
investigating
We can confirm that email processing services in the Australia region have been restored. We will continue to closely monitor performance but email services should now be functioning normally.
monitoring
We are aware that customers in Australia region may be experiencing email delivery delays. We are currently investigating the issue and updates will be posted here as they become available.
investigating
We are aware that customers in Australia region may be experiencing email delivery delays. We are currently investigating the issue and updates will be posted here as they become available.
June 2026
SMS delivery delays
Started:
investigating
Our third-party SMS provider has confirmed that the service incident impacting the delivery of Two-Factor Authentication (2FA) SMS messages has been resolved. All SMS messages are now being delivered successfully.
We will continue to monitor the situation to ensure system stability and consistent message delivery.
monitoring
Our third-party SMS provider has reported an issue that may impact the successful delivery of SMS messages used for Two-Factor Authentication (2FA). The provider is actively working on a resolution, and we will provide updates as they become available.
SMS delivery delays
Started:
investigating
Our third-party SMS provider has resolved their incident and confirmed full service restoration. SMS delivery, including 2FA codes, should now be back to normal. Any messages delayed during the incident window have been processed.
We are monitoring to confirm full recovery on our end and will close this incident within 60 minutes if no further issues are observed.
monitoring
We have identified the root cause of the SMS delivery issue currently affecting some Mimecast customers. Our third-party SMS provider has confirmed the root cause and their engineering team is actively working on a solution.
SMS messages processed during the incident window may experience delays and will be reprocessed once services are fully restored.
Impact: SMS message delivery to recipients may be delayed or unsuccessful, including 2FA authentication codes sent via SMS.
Services affe...
monitoring
We are currently investigating an issue affecting the delivery of SMS messages to recipients. Some customers may experience delays or failures when Mimecast attempts to deliver SMS notifications.
We have identified a potential issue with one of our third-party SMS delivery provider and are actively working with them to determine the root cause and restore full service.
Impact: SMS message delivery to recipients may be delayed or unsuccessful.
Services affected: SMS notifications and aler...
Degraded service impacting Partner Administration Console access
Started:
investigating
We have taken mitigation steps and believe we have resolved the issue impacting access to the Administration Console via the Partner Portal globally.
All services should now be functioning normally. Our Engineering team will continue to closely monitor application availability and performance. We will provide further updates here if necessary.
monitoring
We are continuing to investigate the service disruption impacting Partner Administrators. Administrators are able to successfully log into the Partner Portal; however, when attempting to access customer Administration Consoles via the Partner Portal, they are being logged out.
Our engineering teams remain actively engaged in the investigation. Further updates will be posted here as they become available.
monitoring
We are aware that some Partner Administrators may be experiencing a login loop when attempting to access the Administration Console. We are currently investigating this issue and will post further updates here as they become available.
Administration console access issue
Started:
investigating
We have implemented mitigation steps and believe we have resolved the intermittent issues affecting access to the Mimecast Administration Console for customers hosted on our UK, DE, and ZA grids. Our Engineering team is closely monitoring the situation to ensure a full resolution.
monitoring
We have identified the cause of the intermittent issues affecting customers hosted on our UK, DE, and ZA grids experiencing difficulty accessing the Mimecast Administration Console. Our Engineering team is actively working on implementing a fix and we will provide further updates as they become available.
monitoring
We are aware that some customers hosted on our UK, DE and ZA grid may be experiencing intermittent issues accessing the Mimecast Administration Console. Our Engineering team is actively investigating the issue and we will provide further updates as they become available.
Email Delivery Delays | ZA Grid
Started:
investigating
The email delivery delays affecting customers in ZA have been resolved. We are monitoring to ensure full stability. Further updates will be posted here as they become available.
monitoring
We have identified the cause of the email delivery delays affecting customers in ZA. Engineering are working to resolve this. Further updates will be posted here as they become available.
monitoring
We are aware that customers in ZA grid may be experiencing email delivery delays. We are currently investigating the issue and updates will be posted here as they become available.
Email delivery delays on US grid
Started:
monitoring
We have resolved the email delivery issue affecting Office 365 tenants for US-hosted customers. Mitigation efforts are ongoing for UK and ZA hosted customers, and we will provide further updates as work continues.
monitoring
We have identified the issue impacting email delivery to Office 365 tenants for a subset of US hosted customers and are working to resolve it. We will provide further updates as they become available.
monitoring
We are aware of a service disruption that is impacting email delivery to Office 365 tenants for a subset of US hosted customers. We are investigating this issue and will post further updates here.
Degraded performance on US grid
Started:
monitoring
We have taken mitigation steps and continue to see improved services for previously impacted customers hosted on our US grid. We are continuing our resolution and further updates will be posted here.
monitoring
We believe we have identified the issue affecting a small subset of US-hosted customers and are working to resolve it. We will provide further updates as they become available.
monitoring
We are aware that a small subset of customers hosted on our US grid may be experiencing a degraded service. We are currently investigating the issue and updates will be posted here as they become available.
Degraded Service – Partner Portal Access
Started:
monitoring
We are aware of a service disruption impacting access to the Partner Portal for some customers. Users may be unable to log in or may experience errors when attempting to access the portal.
We are currently investigating the issue and will post further updates here as they become available.
May 2026
German (DE) Mail Processing Degraded
Started:
investigating
We have taken mitigation steps and believe impact to the service has been addressed. While recovery continues, some small mail flow delays may persist as the backlog clears.
Our Engineering team is closely monitoring performance and investigating the cause of the high load. Further updates will be provided as needed.
monitoring
We are aware that some customers hosted on the German (DE) grid may be experiencing degraded service affecting email processing. We are currently investigating the issue, and updates will be posted here as they become available.
Degraded service for SAML authentication on US, USB and UK Grids
Started:
investigating
We have taken mitigation steps and believe we have resolved the issue affecting SAML authentication for customers hosted on our US, USB and UK grids. Successful authentication attempts are now being reported, and we are no longer seeing related errors in our monitoring systems.
Our Engineering team is closely monitoring the situation to ensure continued stability. Further updates will be posted here as they become available.
monitoring
We believe we have identified the issue affecting some customers hosted on our US-B grid who are experiencing failures with SAML login attempts to the Administration Console and associated applications. Our Engineering team is actively investigating the underlying cause and is currently testing a change to validate the suspected configuration issue.
We will provide further updates as they become available.
monitoring
We are aware that some customers hosted on our US-B grid may be experiencing issues with SAML login attempts to the Administration Console and associated applications. Other authentication methods are functioning normally. We are currently investigating the issue and updates will be posted here as they become available.
TTP URL and Browser Isolation Errors on US and USB Grids
Started:
investigating
We have taken mitigation steps and believe we have resolved the issue that caused certain TTP URL links to be incorrectly redirected through Browser Isolation for customers. This was caused by TTP URL links being incorrectly categorized as unknown, resulting in clean links being redirected through Browser Isolation and, in some cases, returning an error. We are now seeing a sustained reduction in Browser Isolation requests and believe service should be returning to normal. We will continue to...
monitoring
We are aware that some customers hosted on our US and USB grids may be experiencing issues accessing rewritten links, where URLs are being redirected through Browser Isolation and may result in an error.
We are currently investigating this issue and will post updates here as they become available. All other Mimecast services are operating as normal.
Administration Console Loading Issues
Started:
monitoring
We are aware that some customers hosted on our ZA grid may be experiencing intermittent issues accessing the Mimecast Administration Console. Our engineering team is actively investigating the issue and we will provide further updates as they become available.
DE Grid - Degraded service impacting Cybergraph and other services
Started:
investigating
We have taken mitigation steps and believe the service degradation issue affecting Cybergraph and other services in the German (DE) grid has been resolved. We are closely monitoring performance and will provide further updates as they become available.
monitoring
We have taken mitigation steps and believe the service degradation issue affecting Cybergraph and other services in the German (DE) grid has been resolved. We are closely monitoring performance and will provide further updates as they become available.
monitoring
We have identified the issue affecting Cybergraph and other services in the German (DE) grid and are working to resolve it. We will provide further updates as they become available.
monitoring
We are aware that some customers hosted on our German (DE) grid may be experiencing degraded service affecting Cybergraph and other services. We are currently investigating the issue, and updates will be posted here as they become available.
April 2026
Aware 1.0 Performance Issue
Started:
investigating
We are observing sustained service improvements, and Mimecast telemetry is showing the error rate has returned to baseline. Customers should see normal processing and application accessibility, although there may be minor delays as any residual backlog clears.
Our Engineering team continues to closely monitor availability and performance.
monitoring
Following our earlier update, mitigation actions have been implemented by Microsoft in relation to the underlying platform disruption impacting the East US region.
We are seeing improved performance for customers on the Aware 1.0 platform; however, there may still be intermittent delays or retries while the environment fully stabilises.
Our Engineering team continues to closely monitor performance and recovery. We will provide further updates here as they become available.
monitoring
We have identified an issue affecting some customers on the Aware 1.0 platform, resulting in delays and retries. This has been attributed to an underlying Azure platform disruption. Our Engineering teams are actively engaged with Microsoft to remediate this as quickly as possible.
Administration Console Loading Issues
Started:
monitoring
We are aware that some customers hosted on our AU grid may be experiencing intermittent issues accessing the Mimecast Administration Console. Our engineering team is actively investigating the issue and we will provide further updates as they become available.
Automatic Threat Remediation non-actionable alerts
Started:
investigating
We are aware that some customers have been receiving alerts for Threat Remediation jobs that do not correspond to actionable items in the Administration Console. Customers in this situation can consider these non-actionable alerts, with no existing threats to remediate. We have identified the underlying cause and have deployed a corrective update. There will continue to be some alerts based on previously identified patterns that will be cleared over time.