Microsoft Office 365 Service is now back to normal operation.
Update, 7:22 p.m. — This issue has been resolved. Network changes by Microsoft on the Office 365 hosting environment caused this issue, which impacted multiple organizations around the world who have Office 365 with co-existing On-Prem exchange deployment. All deferred e-mails previously sent from Office 365 to On-Prem users are starting to deliver to the On-Prem users. Microsoft Office 365 Service is now back to normal operation.
Update, 5:49 p.m. — We are aware there’s currently an Office 365 issue affecting some of our users. E-mail being sent from Office 365 (cloud) is not being received by some on-premise users. The issue affects users in Chancellor's network, SAONet, UCLANet, and the Facilities network. The emails that haven't been delivered are in a pending state, and not lost. Currently, Microsoft Office 365 service health is shown as degraded. We have opened a Premier Service ticket with Microsoft and are working closely with Microsoft Online Services to get this issue resolved as soon as possible. We’ll send out another update when we have more information from Microsoft Online Services.
5:05 p.m. — We’re getting reports that email is not being delivered between Enterprise Messaging (on-premise) and Office365 users. The issue began shortly before noon today, and affects users in Chancellor's Network, SAONet, UCLANet, and the Facilities Network. The emails that haven't been delivered are in a pending state, and not lost. We're investigating the issue, and working to fix the problem.
If your email is affected, or you have questions, please contact the IT Support Center at firstname.lastname@example.org or 310-825-8000.