Why Convert to Shared Mailbox?

When an employee leaves, convert their mailbox to a shared mailbox to maintain access without paying for a license. Shared mailboxes are free up to 50GB.

Method 1: Using Admin Center

  1. Go to Microsoft 365 Admin Center
  2. Navigate to Users ? Active users
  3. Select the user
  4. Click Mail tab ? Convert to shared mailbox
  5. Confirm the conversion

Method 2: Using PowerShell (Faster)

Connect-ExchangeOnline

Set-Mailbox -Identity "user@domain.com" -Type Shared

# Verify conversion
Get-Mailbox -Identity "user@domain.com" | Select-Object DisplayName, RecipientTypeDetails

Step 3: Grant Access to Others

Add-MailboxPermission -Identity "user@domain.com" -User "manager@domain.com" -AccessRights FullAccess -InheritanceType All

Step 4: Remove the License

After conversion, remove the Microsoft 365 license from the user to stop being charged.

Important Notes

  • Shared mailboxes over 50GB require a license
  • Can't login directly to shared mailboxes
  • Mailbox data is preserved during conversion
  • Process is reversible if needed