How can an administrator obtain the token of a specified mailbox user in Zimbra?

You can obtain the token by sending a `DelegateAuth` request to the admin SOAP endpoint (`:7071/service/admin/soap`) using the `zimbraAdmin` namespace. The returned `authToken` can then be used to log into that user's mailbox by adding it as a `ZM_AUTH_TOKEN` cookie on the Zimbra login page. For more details on the Zimbra SOAP API, see the Zimbra SOAP API Development Guide.