Resolved -
Microsoft reports broad recovery and says it has addressed the underlying issue. It continues to restore service for any remaining affected customers and regions.
Mail flow for both Shield and CloudFilter has been operating at normal delivery times. Shield’s Microsoft 365 mailbox notifications are also healthy.
Nov 13, 14:46 EST
Update -
Microsoft reports sustained improvement and continues to address remaining issues.
CloudFilter delivery to Microsoft 365 has improved significantly. Previously delayed messages are continuing to be delivered as the queue clears.
Shield mail delivery has returned to normal. We’re also restoring the connections that notify Shield about changes in some Microsoft 365 mailboxes. Until those connections are restored, some mailbox activity may take longer to appear in Shield.
We’re monitoring both services as recovery continues.
Nov 13, 11:18 EST
Update -
Microsoft reports that its email queues have significantly decreased and are approaching normal levels. It continues to restore affected infrastructure and investigate remaining issues.
Shield mail flow has returned to normal delivery times, and its mail queues have caught up. Some Shield feature notifications are still being processed and may be delayed.
CloudFilter continues to deliver queued messages to Microsoft 365, though Microsoft is still temporarily deferring some deliveries. We’re continuing to monitor the situation.
Nov 13, 09:09 EST
Monitoring -
Delivery to Microsoft 365 from both Shield and CloudFilter has improved significantly, and delayed messages are being delivered. Shield’s connection to Microsoft 365 mailboxes also appears to be working again. We’re processing the backlog of queued email and mailbox notifications, and some delays may continue while we catch up.
Microsoft reports broader improvement in North America and sustained improvement across much of Europe, but says intermittent issues and delivery delays may continue. We’re continuing to monitor the situation.
Nov 13, 08:13 EST
Update -
Microsoft is testing a configuration change to address an overwhelmed process on affected servers. It has also begun reverting a recent network configuration change and is monitoring the results. Microsoft has not yet confirmed that service has recovered.
Shield’s access to Microsoft 365 mailboxes and email delivery to Microsoft 365 through both Shield and CloudFilter remain affected. We’re continuing to monitor the impact and will share updates as more information becomes available.
Nov 12, 20:18 EST
Update -
Microsoft continues to restart and validate affected servers as it works to restore service. Shield’s access to Microsoft 365 mailboxes and email delivery to Microsoft 365 through both Shield and CloudFilter remain affected.
Our changes to isolate Microsoft-bound traffic have improved mail flow to other providers. We’re continuing to monitor the situation and will share updates as more information becomes available.
Nov 12, 16:58 EST
Update -
We’ve made changes to isolate traffic destined for Microsoft 365 and reduce delays for mail going to other providers. Delivery to Microsoft 365 remains affected. We’re continuing to monitor mail flow.
Nov 12, 15:09 EST
Update -
Microsoft has begun redistributing connection traffic and restarting affected servers to reduce the impact of its ongoing service disruption. Some connectivity issues and email delivery delays may continue while Microsoft works to restore service.
We’re continuing to monitor the impact on Shield and CloudFilter and will share updates as we learn more.
Nov 12, 14:42 EST
Identified -
Microsoft is investigating an Exchange Online issue affecting mailbox access in the Americas. Microsoft is tracking the issue as EX1550543.
We’re seeing Microsoft Graph API errors that are affecting Shield’s ability to access Microsoft 365 mailboxes. We’re also seeing Microsoft’s servers temporarily defer messages from Shield and CloudFilter, resulting in email delivery delays for affected Microsoft 365 customers.
This issue originates with Microsoft and is not caused by Shield or CloudFilter. Our team is monitoring the impact and investigating options to mitigate delivery delays. We’ll share updates as we learn more.
Nov 12, 13:35 EST