Do you know of a way to track emails that are opened in Outlook 2007? Outlook 2007 doesn’t allow external images/ tracking beacons.

By tracking, I mean that we want to be able to know if someone opened the email - that's the intent. With most email clients, we can embed a URL with a query string on it that is unique for each person the email is sent to and thus see if the email was opened, but Outlook 2007 does not allow external links, so this process won't work with people who open their email in Outlook 2007.

Is there a way to know if someone opens an email in Outlook 2007?