Hornetsecurity outage history

October 6, 2026 12:22 CEST Investigating - We are currently investigating delays affecting the Hornet E-Mail service. Users may notice a delay before newly received emails appear in the webmail client. October 6, 2026 13:40 CEST Identified - The root cause has been identified, and our team is actively working on a fix. October 6, 2026 16:11 CEST Monitoring - The fix has been deployed. Inbound emails are now flowing normally into webmail, and we will continue to monitor system stability before marking this incident resolved. October 7, 2026 11:01 CEST Monitoring - The fix has been deployed. Inbound emails are now flowing normally into webmail, and we will continue to monitor system stability before marking this incident resolved. October 7, 2026 14:44 CEST Resolved - This incident is now resolved. The fix has been verified, all delayed inbound emails have processed, and webmail delivery is operating as expected.

September 28, 2026 14:43 CEST Scheduled - We plan to release a major version 6.64.0.0 of the Control Panel on 2026-10-07 at 09:45am UTC+2 This release contains functional upgrades and bug fixes. No downtime is expected, and the Control Panel service will remain available throughout the maintenance time window. Other services and email flow will not be affected by this maintenance. October 7, 2026 11:00 CEST Active - The maintenance has been started. October 7, 2026 11:04 CEST Completed - Maintenance has been completed.

September 30, 2026 08:54 CEST Investigating - The Email Live Tracking is only available with a degraded performance. The cause is currently being analyzed in more detail. Other services and email flow are not affected. September 30, 2026 10:12 CEST Monitoring - The Email Live TrackinService is operational again. The incident is currently still being monitored. September 30, 2026 15:19 CEST Resolved - The cause of the incident has been resolved. The Email Live Tracking is again fully operational and solved sustainably.

September 9, 2026 08:52 CEST Scheduled - We plan to release a major version 6.63.0.0 of the Control Panel on 2026-09-23 at 09:45am UTC+2 This release contains functional upgrades and bug fixes. No downtime is expected, and the Control Panel service will remain available throughout the maintenance time window. Other services and email flow will not be affected by this maintenance. September 23, 2026 09:49 CEST Active - The maintenance has now started. September 23, 2026 11:08 CEST Completed - Maintenance has been completed.

September 17, 2026 10:31 CEST Investigating - The Hornetsecurity website is currently not available. The cause is currently being analyzed in more detail. Other services and email flow are not affected. September 17, 2026 10:32 CEST Identified - The Hoster found the root cause within a failed update on their system and is currently working on a solution. September 17, 2026 11:56 CEST Monitoring - The hosting provider has resolved the underlying cause, and all websites are fully accessible again. We are continuing to monitor the situation closely. September 18, 2026 13:23 CEST Resolved - Incident resolved by hosting provider. All websites are fully accessible.

September 17, 2026 08:30 CEST Investigating - Between 16 September 2026, 17:00 CEST and 17 September 2026, 08:23 CEST, Hornetsecurity introduced a new URL rewriting scheme as part of a capacity expansion of the Secure Links service in France. The change was rolled out progressively to approximately 1200 randomly selected tenants. During this period, Microsoft classified some URLs rewritten with the new scheme as suspicious. Users who clicked these links were shown a Microsoft Safe Links warning. The issue affected rewritten URLs under both the atpscan.global.* and secure-links.* domains. Tenants outside the rollout scope were not affected. September 17, 2026 12:00 CEST Resolved - Hornetsecurity detected the issue through monitoring. We immediately initiated a rollback of the change and raised an incident with Microsoft. The previous URL rewriting scheme was restored for all users at 08:23 CEST on 17 September 2026.

September 13, 2026 12:48 CEST Identified - The 365 Total Backup Service is partially disrupted for a small subset of tenants on the DE Region. The root cause has already been identified and our Technical Teams are currently working on a solution. We will keep this space updated as soon as we have an update on the progress. All other services and regions are not affected. September 14, 2026 09:33 CEST Resolved - The cause of the incident has been resolved. The 365 Total Backup Service (DE Region) is fully operational.

September 2, 2026 12:05 CEST Investigating - We are currently investigating reports that newly created configurations are not being deployed as expected. Email delivery and other services are not affected. September 2, 2026 15:34 CEST Identified - We have identified the cause of the isolated configuration propagation issues and deployed a fix. The pending configuration changes will be applied gradually, and new configurations will be propagated as expected. September 2, 2026 22:47 CEST Monitoring - Since the fix was deployed, we can confirm that changes are now being applied in a timely manner. We are currently monitoring the system to ensure that configuration propagation remains stable before closing the incident. September 3, 2026 11:58 CEST Resolved - The incident has been resolved. Configuration deploys are back to normal.

August 31, 2026 18:28 CEST Scheduled - We plan to release a major version 6.62.0.0 of the Control Panel on 2026-09-02 at 01:30pm UTC+2 This release contains functional upgrades and bug fixes. In some cases, access to the Control Panel may be limited during the maintenance window. Other services and email flow will not be affected by this maintenance. September 2, 2026 14:51 CEST Active - Update to major version 6.62.0.0 of the Control Panel has started. September 2, 2026 14:59 CEST Active - Update to major version 6.62.0.0 of the Control Panel is running. September 2, 2026 15:30 CEST Completed - Update to major version 6.62.0.0 of the Control Panel has been completed.

August 10, 2026 17:17 CEST Investigating - The 365 Total Backup Service is only available with a degraded performance for a small subset of tenants on the Canada Region. The cause is currently being analyzed in more detail. The 365 Total Backup Service is unaffected on other Regions. Other Services and Email Flow are also NOT affected. August 11, 2026 14:42 CEST Identified - Our technical team has successfully identified the root cause of the 365TB issue affecting the CA Region. Our team is working around the clock to implement a permanent, sustainable fix. We appreciate your continued patience and understanding as we work to restore full system stability. We will be updating this space as soon as new information becomes available. August 12, 2026 16:00 CEST Identified - Our Engineering and Operations Teams are still actively focused on implementing a definitive solution for the CA Region. In the meantime, we are currently also performing some tests and calculations in order to work out an ETA, which we can share. August 13, 2026 16:18 CEST Identified - Our Technical Team has just finished developing a fix for the 365TB issues on the CA Region. This fix is currently being tested by our QA Team and will be deployed as soon as it gets the greenlight. If everything goes well, we will be aiming to rollout this fix by tomorrow. August 14, 2026 17:23 CEST Identified - Our engineering team wrapped up the initial fix, but we ran into a possible issue during QA testing. To prevent any downside or risk, we need to run a few more tests and validate everything properly. The release will therefore be pushed back slightly to allow for extended automated testing throughout the weekend, with the rollout now expected early next week. We appreciate your patience as we make sure this fix is thorough before it goes live. August 17, 2026 17:24 CEST Identified - Our Technical Team is scheduled to deploy the fix tomorrow morning, pending the final automated tests running this evening. Following the deployment, systems are expected to begin a gradual recovery as early as tomorrow afternoon. Performance will be monitored closely, and further updates will be provided as operations return to normal. Thank you for your continued patience. August 18, 2026 15:29 CEST Monitoring - Our Technical Team has successfully deployed the fix on the CA Region. Systems are recovering at a steady pace, with 75% of the affected tenants already back to normal. Performance will continue to be monitored closely, and we will share a final update once systems are fully recovered. We appreciate your understanding throughout this process. August 19, 2026 18:10 CEST Monitoring - Our Technical Team reports that system recovery is continuing to progress at a gradual pace. We will continue to closely oversee the performance and provide updates as recovery continues. August 20, 2026 16:02 CEST Monitoring - The final phase of system recovery is taking longer than initially anticipated, however we are seeing steady progress and are estimating a full recovery by mid-next week. Performance is being closely monitored as we work through these final steps. We apologise for the inconvenience such delays may have caused, and we will make sure to communicate any updates as we get them. August 21, 2026 15:28 CEST Monitoring - The final phase of system recovery is progressing as planned. System performance will continue to be closely monitored throughout the weekend, with further updates provided as they become available. Thank you for your continued patience and understanding. August 24, 2026 17:59 CEST Monitoring - Weekend monitoring identified issues that slowed recovery and required the process to be restarted using improved tools. Recovery is expected to continue throughout the week, with completion anticipated toward the end of the week. We will continue to monitor progress and provide timely updates in the coming days as the service gradually improves for tenants in the CA region. We apologize for the delay. Our Product and Systems Engineering teams remain fully engaged and are working to restore all systems as efficiently as possible. August 25, 2026 15:14 CEST Monitoring - Restoration using the improved tools is progressing steadily and expected timelines remain unchanged, and a substantial number of tenants has already been successfully recovered. Our Engineering teams remain fully focused on completing a stable and thorough recovery and we will continue to provide timely updates throughout the week. Thank you for your continued cooperation and patience. August 26, 2026 14:55 CEST Monitoring - We are continuing to see steady and timely progress across all remaining restoration tasks. Our timeline toward the end of the week is on track as expected. Further updates will be provided as we advance further into the final phases of recovery. Thank you for your continued patience. August 27, 2026 17:56 CEST Monitoring - The recovery operation has been successfully completed, and the CA region infrastructure is back online. Tenant backups are being processed, although some customers may continue to see a "transient issues" message in the UI while the backlog is cleared, these issues should be automatically cleared as successful backups progress across the region. Our teams are closely monitoring progress and expect the backlog to be resolved shortly. A final confirmation will be provided once full operational status has been restored and all backlog has been cleared. August 28, 2026 19:04 CEST Monitoring - System Recovery on the CA Region is nearly finalized. All OneDrives, SharePoint Sites, and Teams environments are now fully protected and operational, leaving only 30% of Mailboxes remaining to complete their latest backup and also be fully protected. Engineering Teams remain fully engaged to finalize the remaining mailboxes' recovery. A final confirmation will be shared as soon as the entire process is officially completed. Thank you for your continued patience. August 29, 2026 15:04 CEST Resolved - All backlog has now been cleared and backup operations have completed successfully across all tenants. The root cause of the incident has been successfully resolved, and the 365 Total Backup Service on the CA Region is once again fully operational and resolved sustainably. All validation checks confirm normal system behaviour across the board. Thank you for your exceptional patience and cooperation throughout this recovery process.

August 18, 2026 20:28 CEST Scheduled - We plan to replace our current TLS certificates for hornetsecurity.com on 2026-08-19 at 10:00 AM CEST. All services will remain available during the maintenance window, and email flow will not be affected by this maintenance. Further information can be found in our Knowledge Base: https://support.hornetsecurity.com/hc/en-us/articles/360012192677-Required-SSL-TLS-Information-for-Business-Partners No downtime is expected. August 19, 2026 10:05 CEST Active - The maintenance has been started. August 19, 2026 18:05 CEST Active - The maintenance has been successfully completed. August 19, 2026 18:07 CEST Completed - Closing this notification as the maintenance has been successfully completed.

August 10, 2026 12:16 CEST Scheduled - We plan to release Major Version 6.61.0.0 of the Control Panel on August 18, 2026. You will find further release details in the Release Notes: https://www.hornetsecurity.com/en/release-notes/. Due to the nature of this release, there might be functional upgrades and updates, as well as bug fixes. Email flow will not be affected. August 18, 2026 13:31 CEST Active - Maintenance has started August 18, 2026 14:31 CEST Active - The maintenance is still in progress. August 18, 2026 15:01 CEST Completed - The maintenance has been completed.

July 31, 2026 13:59 CEST Scheduled - We plan a maintenance of the Websafe service: 2026-08-04 at 02:00pm CEST Due to the nature of this release, there might be functional upgrades and updates alongside with Bugfixes. The Websafe service will have some limitations during this timeframe. Impact: Limited visibility of mails in last 24 hours Possible delay of the websafe emails delivery Possible full downtime up to 10 min August 4, 2026 16:10 CEST Active - Maintenance has started August 4, 2026 16:21 CEST Completed - The maintenance of the websafe service has been completed.

July 10, 2026 18:14 CEST Scheduled - We will be performing a database re-synchronisation for 365 Permission Manager over the weekend. During this maintenance period, the application will be unavailable. Users may be able to access the login page, but after signing in they will encounter errors in the console and all product functionality will remain unavailable. Service will be restored once the re-synchronisation has been completed. We apologise for the inconvenience and appreciate your understanding. July 10, 2026 18:34 CEST Active - Scheduled Maintenance has started. July 11, 2026 11:36 CEST Completed - Scheduled Maintenance has ended and 365 Permission Manager is fully available again.

June 2, 2026 12:14 CEST Scheduled - We plan to release Major Version 6.57.0.0 of the Control panel on this day: 2026-06-13 10:15am CEST Due to the nature of this release, there might be functional upgrades and updates alongside with Bugfixes. The Control Panel won't be available during the maintenance window. Other services and email flow will not be affected by this maintenance. June 13, 2026 10:15 CEST Active - Update to major version 6.57.0.0 of the Control Panel will start now. The Control Panel won't be available during the maintenance window. Other services and email flow will not be affected by this maintenance. June 13, 2026 12:03 CEST Completed - Update to major version 6.57.0.0 of the Control Panel has been completed. The Control Panel is now fully operational.

June 2, 2026 16:48 CEST Investigating - We are currently observing reports of emails being deferred when the receiving Host is a Microsoft Tenant. From our current findings this seems to only affect German M365 Tenants. The behavior can be identified by following SMTP Code: 421 4.3.2 The maximum number of concurrent connections per resource forest has exceeded a limit, closing transmission channel Affected emails are in the deferred state. We are trying to deliver inbound deferred emails for up to 7 days and outbound emails we are trying to deliver up to 24 hours. Other services are not affected. June 2, 2026 17:32 CEST Monitoring - Microsoft is working to resolve the observed issue as soon as possible. More Details can be found here: https://admin.cloud.microsoft/#/servicehealth/:/alerts/EX1331830 We are monitoring the situation closely. Other services are not affected. June 3, 2026 00:57 CEST Resolved - We now observe stable email delivery to all M365 environments. Previously deferred emails have also been successfully delivered. M365 Admins can access more information here: https://admin.cloud.microsoft/#/servicehealth/:/alerts/EX1331830.

May 27, 2026 15:33 CEST Scheduled - We plan to release a major version 6.56.0.0 of the Control Panel on 2026-05-28 at 03:30pm UTC+2 This release contains functional upgrades and bug fixes. No downtime is expected, and the Control Panel service will remain available throughout the maintenance time window. Other services and email flow will not be affected by this maintenance. May 28, 2026 15:30 CEST Active - Update to major version 6.56.0.0 of the Control Panel will start now. May 28, 2026 15:44 CEST Completed - Scheduled Maintenance has been completed.

May 6, 2026 14:59 CEST Scheduled - We plan to release a major version 6.55.0.0 of the Control Panel on 2026-05-07 at 03:20pm UTC+2 This release contains functional upgrades and bug fixes. No downtime is expected, and the Control Panel service will remain available throughout the maintenance time window. Other services and email flow will not be affected by this maintenance. May 7, 2026 15:20 CEST Active - Update to major version 6.55.0.0 of the Control Panel will start now. May 7, 2026 15:37 CEST Completed - Scheduled Maintenance has been completed.

April 7, 2026 16:32 CEST Scheduled - We plan to release a major version 6.53.0.0 of the Control Panel on 2026-04-08 at 03:00pm UTC+2 This release contains functional upgrades and bug fixes. No downtime is expected, and the Control Panel service will remain available throughout the maintenance time window. Other services and email flow will not be affected by this maintenance. April 8, 2026 15:03 CEST Active - Update to major version 6.53.0.0 of the Control Panel will start now. April 8, 2026 15:26 CEST Completed - Scheduled Maintenance has been completed.

March 26, 2026 12:05 CET Identified - Microsoft incident reference: EX1259460 Issue Description: Some users may be unable to access custom add-ins through any Exchange Online connection method. Latest updates from Microsoft: 26/03/2026 9:04:00 PM – Microsoft is investigating the possibility that incoming traffic may not be appropriately balanced throughout the affected environment while also continuing to review the previously identified exception to determine the root cause and a strategy that remediates impact. 25/03/2026 8:35:00 AM – Microsoft hasn't confirmed a viable workaround, however they have identified an authentication-related exception which may be contributing to the impact, and they are further reviewing this exception to aid in their root cause analysis. Should you wish to follow updates from Microsoft directly you may do so from the Microsoft Service Health Dashboard under ID EX1259460 https://learn.microsoft.com/en-us/microsoft-365/admin/manage/health-dashboard-overview If you are impacted by this and are unable to wait for a resolution from Microsoft, you may find available workarounds as below: Total Protection Outlook Add-in Workaround http://support.hornetsecurity.com/hc/en-us/articles/21797951259537-Manual-installation-of-the-Outlook-add-in AIRV Outlook Add-in Workaround http://cp.hornetsecurity.com/manual/en/ai_recipient_validation/t_deploy_ai_recipient_validation_add_in_manually.html April 1, 2026 10:39 CEST Resolved - Microsoft incident ID EX1259460 has been set to status "Service Restored". Below is the final status posted by Microsoft: We’ve identified that a recent Exchange Web Services (EWS) deprecation update and an Exchange Online authentication change prevented users from accessing custom add-ins in Outlook. To remediate this issue, we rolled back both offending changes and verified through service monitoring that this action successfully resolved the impact. Admins that have disabled EWS may continue to experience this issue and we recommend that admins re-enable EWS at this time. For additional guidance on managing Exchange Web Services, please refer to the following: https://learn.microsoft.com/en-us/exchange/client-developer/exchange-web-services/how-to-control-access-to-ews-in-exchange Scope of impact: Some users who are attempted to access custom add-ins through all Exchange Online connection methods may have been impacted. Start time: Thursday, March 12, 2026, at 10:04 PM UTC End time: Friday, March 27, 2026, at 1:40 AM UTC Root cause: A recent EWS deprecation update and an Exchange Online authentication change prevented users from accessing custom add-ins in Outlook. Next steps: - We’re reviewing how the impacting changes prevented users from accessing custom add-ins so we can avoid similar issues in the future, as EWS is slated to be deprecated by October 2026. This is the final update for the event.