This issue has been resolved. We are no longer seeing email delays.
Posted Jan 23, 2026 - 05:56 PST
Update
We are continuing to monitor the situation as MS365 is returning services to normal. Email delays are still occurring into the Exchange environment.
Posted Jan 22, 2026 - 17:18 PST
Update
We are starting to see some of normalization of MS365 services. There are deferred deliveries from 90-120 minutes ago, but there are still service/performance issues which we will continue to monitor and document.
Posted Jan 22, 2026 - 14:49 PST
Update
We are continuing to investigate this issue.
Posted Jan 22, 2026 - 14:30 PST
Update
We are continuing to investigate this issue.
Posted Jan 22, 2026 - 14:09 PST
Investigating
ITS is continuing to investigate the cause of issues with Microsoft 365.
Microsoft has identified an issue where users may be seeing degraded service functionality or be unable to access multiple Microsoft 365 services. Users may be receiving a "451 4.3.2 temporary server issue" error message when attempting to send or receive email through Outlook and Exchange. Other impacted functions can be viewed on the Microsoft status page:
Thank you for your continued patience as our team works to restore these services as quickly as possible. Updates and additional details will be shared here as they become available. If you notice any additional issues or impact, please contact the ITS Service desk at https://support.ucsd.edu, support@ucsd.edu or at (858) 246-4357.
Posted Jan 22, 2026 - 14:08 PST
This incident affected: Communication and Collaboration.