This incident has been resolved. All messages have been delivered.

We have identified the root cause of the issue and have implemented a fix. All messages that were delayed due to this issue are now being processed and delivered immediately by our system. We continue to monitor the environment to ensure normal operation. A detailed incident report, including the root cause analysis and corrective actions, will be shared as soon as possible.

We are currently investigating an issue that appears to be related to SSL certificate validation on Microsoft servers affecting Microsoft 365 services in the EU region (semi-inline scope), which may impact message delivery. Our system will automatically retry sending any affected messages. We are actively monitoring the situation and will provide further updates as soon as more information becomes available from Microsoft or the issue status changes.