We've now resolved the incident. Outlook Desktop will be disabled and Outlook Web will be in use again. Thanks for your patience.
The service has recovered for the majority of users. Our external provider is working to ensure the service recovers for all users.
There is currently some disruption to the Outlook Web system. You may receive a "503 Service Unavailable" error. We are working with our external provider to resolve this issue promptly.
Outlook Desktop has been re-enabled during this period to allow access to emails.