Restarting the affected infrastructure has resolved the issue.
Update: 9:20 a.m. — Restarting the affected infrastructure has resolved the issue. Microsoft is continuing to monitor the service and is reaching out to some of the affected customers to validate resolution.
Update: 7:00 a.m. — Microsoft is continuing to restart the affected infrastructure, which is expected to take approximately 1.5 hours to complete.
Update: 9:00 p.m. — Microsoft has begun deployment of the fix to the affected infrastructure, and are monitoring its progress to ensure it completes successfully.
Update: 7:00 p.m. — Microsoft is finishing testing the proposed fix. Once they've verified that it resolves the issue, they will proceed with deployment.
Update: 5:59 p.m. — Microsoft has determined that a recent update introduced an issue impacting service availability, and they're preparing to deploy a fix to remediate impact.
We’re getting reports that some Office365 users are unable to access their email. Users may be unable to access their mailbox from Outlook, Outlook on the web, mobile devices, or other protocols. Microsoft has identified a potential issue impacting availability of the Exchange Online service. Microsoft is reviewing diagnostic and telemetry data to isolate the cause of the problem.
We will update when we know more. If you’re one of the affected users, or would like more details, please contact us at (310) 825-8000 or firstname.lastname@example.org.