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Status Page
Fri Jul 18 2025 @ 8:48PM ADT
This page offers information for Dalhousie services. Check back here any time to view the current status of the services listed below. For all other information or to report a problem, please contact the ITS Service Desk (902-494-4357) or toll-free (1-800-869-3931)..
O365 - Email/Outlook
2025-07-14 Status Description
02:51 PM Notice 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 Notice 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 Notice 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.