1. Using Microsoft 365
You can convert a user mailbox to a shared mailbox through either the Exchange Admin Center or PowerShell.
a. Exchange Admin Center
- Sign in to the Exchange admin center.
- Navigate to Recipients > Mailboxes.
- Select the user mailbox you want to convert.
- Click “Convert to shared mailbox”.
- Confirm the conversion when prompted.
b. PowerShell
- Open an Exchange Online PowerShell session.
- Run the following command:
Set-Mailbox -Identity <MailboxIdentity> -Type Shared- Confirm mailbox conversion.
Recommendation
Once the mailbox is converted to shared, you can remove its license if direct user access isn’t required. Removing unnecessary licenses helps optimize costs (shared mailboxes don’t require a license unless over 50GB or using in-place archive features).
For more information check the Convert a mailbox in Exchange Online article.
2. Using CoreView
You can use CoreView to convert user mailboxes to shared mailboxes in bulk or individually.
- Go to the CoreView app.
- Select ACTIONS > Management Actions > Mailbox > Convert to shared mailbox.
- Select one or more user mailbox(es) or upload a CSV file with the list of targets.
- Click Continue > Proceed.
- Optionally, enter notes (such as a ServiceNow ticket number or the reason for the change) for audit and tracking purposes in CoreView.
- The selected mailboxes are converted to shared mailboxes.
Operators can only view and manage mailboxes within their assigned V-Tenant scope.