Status Page

O365 - Email/Outlook

2025-07-14	Status	Description
02:51 PM		EXCHANGE NOTICE Organizations that leverage Proofpoint may be unable to send Exchange Online email messages Service Dis More info: Users may see email deferrals with Reason: [{LED=450 4.4.312 DNS query failed [Message=ServerFailure] key for validation pphosted.com. is marked as invalid because of a previous signature crypto failed Proofpoint are providing updates here: https://proofpoint.my.site.com/community/s/proofpoint-current-incidents Current status: The service provider is directing organizations to contact Proofpoint should they require further assistance.

2025-07-11	Status	Description
11:14 AM		EXCHANGE NOTICE Users may be unable to access their mailbox using any Exchange Online connection method Restoring Service Current status: The fix to resolve the underlying cause of impact saturated 71 percent of the affected infrastructure, and service availability remains healthy. Out of an abundance of caution, the service provider has intentionally slowed down the rollout to ensure there are no disruptions during peak business hours. Based on their telemetry, they’ve seen no further impact since their initial mitigation steps were completed. They’ll continue to closely monitor the service for any variances until the underlying issue is resolved.
10:47 AM		Status Service Restored Impacted services Exchange Online itle: Users may be unable to access their mailbox using any connection methods User impact: Users may have been unable to access their mailbox using any connection methods. More info: Impacted connection methods included, but may not have been limited to: - Representational State Transfer (REST) API - Outlook on the web - Exchange ActiveSync (EAS) - Messaging API (MAPI) Final status: The configuration change has fully saturated in all affected infrastructure. We've verified that the service is healthy by monitoring telemetry and confirming resolution with previously affected customers. Scope of impact: Users attempting to access their Exchange Online mailbox using any connection methods may have been impacted. Start time: Wednesday, July 9, 2025, at 10:20 PM UTC End time: Thursday, July 10, 2025, at 4:41 PM UTC Preliminary Root Cause: A recent service update to an authentication component unintentionally prevented access for a subset of users, resulting in intermittent service unavailability. Next steps: - We're analyzing performance data and trends on the affected infrastructure to help prevent this problem from happening again. - We're working to better understand the underlying cause of the event so that we can prevent similar issues from happening in the future, and to improve service resilience. We'll provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business days.