Private post viewable via email only

[montym]

I have a private forum set up, so that each user only sees their threads/posts. We want them to be able to have the option to show threads or posts to people who aren't registered via email.

The email this page function is enabled. Of course, when you click on the link from the email it asks you to login, register or, if you're already logged in as a different user, tells you that you can't access the thread.

I'd like to know if there's a way that someone could access the private threads as read-only if it were transmitted to them via email? And again, that would be the only way that anyone other than the owner would be able to see the thread publicly -- via that email generated link.