Upcoming deletion of migrated campus shared mailboxes and calendars

Beginning in December 2026, Information Technology (IT) will permanently delete shared mailboxes and calendars that were migrated from the UC Davis campus Microsoft 365 environment to the new UC Davis Health Microsoft 365 environment. 

A shared mailbox or calendar is an email account that multiple users can access, such as a department or team mailbox or calendar. 

Once these campus shared mailboxes and calendars are deleted, any automatic forwarding from the campus mailbox to the corresponding UC Davis Health mailbox will stop. 

What you need to do 

If your team uses a migrated calendar or shared mailbox and has published or shared the old email address, you will need to update any references to the old campus email address with the new UC Davis Health shared mailbox address before the deletion occurs. 

Examples of where old email addresses may appear include: 

• Intranet/webpages 

• Business cards 

• Email signatures 

• Printed materials 

• Internal documentation or forms 

• External communications (mass mailings, vendors, etc.)  

Which shared mailboxes and calendars will be deleted? 

View the list of shared mailboxes scheduled for deletion here.  

View the list of shared calendars scheduled for deletion here.  

Will non-migrated shared mailboxes and calendars be deleted?  

No. Only shared email mailboxes and calendars that were migrated to the UC Davis Health Microsoft 365 environment will be deleted. Shared mailboxes and calendars that remain in the UC Davis campus environment and were not migrated will be managed by the UC Davis campus team.  

Why are migrated shared mailboxes and calendars being deleted?  

Deleting the migrated campus shared mailboxes and calendars is part of the Microsoft 365 migration and helps ensure UC Davis Health data is fully removed from the campus environment, improving security and reducing duplicate resources. 

What happens after the shared mailbox or calendar is deleted?  

After deletion, the shared mailbox or calendar will enter a brief “soft delete” period during which IT can recover and restore data if needed. Once that recovery window closes, the mailbox or calendar and its contents will be permanently removed and cannot be restored.  

If a shared mailbox or calendar was deleted in error, please submit an IT ticket (linked below) immediately to have it restored.  

Resources and support 

If a shared mailbox or calendar is scheduled to be deleted, and shouldn’t be, please submit a ServiceNow ticket by November 20.  

• Microsoft 365 Issues – IT Self Service (select Outlook/OWA Issue from the drop-down menu) 

• Nov. 20, 2026 is the last day to submit a ticket to remove a shared mailbox or calendar from the list. 

• See the list of shared mailboxes scheduled for deletion here. 

• See the list of shared calendars scheduled for deletion here. 

• For additional assistance, please contact the Technology Operations Center at 916-734-4357 (HELP).