That's exactly how it works, Lisa. As long as you're logged in (and have access to the folder), the link works for you. As long as you're not logged in, you get the message that this was a restricted folder. I think I once previewed a message with a link to the nfic folder and logged out before clicking on the link to test it. (And, no, I didn't actually send the message, I only wanted to find out if access is indeed restricted to logged-in members with access to the nfic folders.) You might want to try it, Labby.
