Codetwo Status

Microsoft reports in EX1331830 that their configuration changes have reached approximately 50% of the affected infrastructure and message queues are steadily improving. This is also confirmed by our telemetry. More information can be found in the Microsoft 365 Admin Center under EX1331830 (https://admin.cloud.microsoft/#/servicehealth/:/alerts/EX1331830), if accessible. CodeTwo is and has been operating normally throughout this incident. All emails were delivered with signatures attached. As the issue is no longer affecting our mail flow and is not related to CodeTwo infrastructure, we are resolving it. Our teams will continue to monitor the situation 24/7/365.

# Summary On March 18, 2026, a small subset of CodeTwo customers experienced temporary issues with email delivery. The incident was caused by a Microsoft networking and DNS‑related issue within Microsoft 365 infrastructure and was not the result of a failure in the CodeTwo service. # Impact * Only a limited number of customers were affected. * The issue occurred intermittently. * The impact was limited to customers whose mail flow depended on Microsoft 365 services affected by the incident. # Root cause Microsoft confirmed that the incident \(ID MO1255228\) was caused by a temporary issue with their networking infrastructure, where part of the infrastructure intended to handle production traffic was only partially reinstated. This led to DNS and load‑balancing issues, affecting services such as Exchange Online. The incident originated entirely within Microsoft’s infrastructure and was outside of CodeTwo’s control. # Resolution Microsoft manually reinstated the full networking infrastructure and confirmed service health recovery. Following this action, telemetry indicated stable and healthy service operation. # Why CodeTwo was affected CodeTwo services integrate directly with Microsoft 365 and Azure and rely on Microsoft‑managed DNS and networking components. DNS failures at the Microsoft platform level affect all services integrated with Microsoft 365, including third‑party solutions. There is no technically viable way for any Microsoft 365-integrated service to be fully immune to platform‑level DNS or networking failures on Microsoft’s side. # Preventive measures * CodeTwo services are monitored 24/7/365. * We operate redundant and failover‑capable infrastructure. * In case of Microsoft‑side incidents, we take all actions within our control to minimize customer impact, including traffic rerouting where technically possible. Microsoft stated that this type of incident has been extremely rare and committed to improving safeguards to prevent similar events in the future. # Current status Microsoft has confirmed that the affected services were fully restored and operating normally. No further issues related to this incident have been observed.

This incident has been resolved.

The fix implemented by the MS Exchange Online team worked and our service is fully operational again. The most recent update from Microsoft: "We’re continuing to see steady improvements in service availability for Exchange Online and Microsoft Teams and our broader recovery efforts remain actively underway. Engineers are further refining load balancing measures to accelerate recovery and are methodically addressing the remaining impacted services."

This incident has been resolved.

Microsoft has published official information about this incident on the Service Health Dashboard (SHD) under ID: EX1183800. Please refer to the SHD for more details. Since this officially confirms that the issue was not related to CodeTwo, we are resolving this incident on our end. If you have any questions, please raise a service request with Microsoft. You are also welcome to contact our Support Team at: https://www.codetwo.com/company/contact. All CodeTwo services have been operational during the incident. Thank you for your understanding and cooperation.

The issue appears to be resolved now. A bunch of guys were about to turn blue (when we realized Microsoft has messed up the DNS configuration) - we're breathing again. Thank you for your patience and understanding! This was a widespread incident affecting multiple Microsoft resources worldwide. Some of the performance issues we experienced as a result were unavoidable. Nevertheless, we’ll continue to enhance our high availability capabilities to make our are services more resilient to similar problems in the future. Please stay tuned, and thank you for your continued trust and business. If you have any questions or need assistance, please reach out to our Customer Success Team - we’re online 24 hours a day. And yes, our SOC Team also works around the clock, continuously monitoring our services both reactively and proactively. These teams, along with our Product Team, will remain on “DEFCON 1” until we’re certain the issue has been fully mitigated.

This incident has been resolved.

It looks like the incident affected only a handful of tenants in Australia East, and the overall impact was very limited and not related to CodeTwo. We’re not seeing any issues with our services, so we’re closing this incident. Our 24/7/365 Proactive Monitoring Team will continue to actively monitor the service. If you are experiencing any problems, please feel free to reach out to our Support Team - we’re available around the clock.

The problem has been resolved by Microsoft. For further information, please check Service health in the Microsoft 365 Admin Center (Incident ID: EX1144276). CodeTwo is operating and has been operating normally. All emails were delivered with signatures attached.

The scheduled maintenance has been completed.

The scheduled maintenance has been completed.

The scheduled maintenance has been completed.