Microsoft might be doing something tricky. Or I could be paranoid. It's been the policy of free webmail providers to add a tag line at the end of all outgoing emails. This one came to me via a Hotmail email: "Get your FREE download of MSN Explorer at http://explorer.msn.com." Pretty benign, no? Well, the email was actually sent as HTML. The URL in the text of the message wasn't actually the same as the URL specified in the HREF attribute of the anchor tag. That URL was: http://g.msn.com/1HM105401/44. Now, that looks like a rather randomly generated path on the end of that. Pardon me while I go all "UN Black helicopter" conspiracy crazy on you, but that would be the way I'd do it if I wanted to know which emails resulted in clicks to MSN. Just generate a random string for every outgoing email, save it as well as pertinent information about the email (recipient, sender, maybe more), and keep track of who comes to those links. Why they'd want to do that is beyond me, but I can't think of a legitimate reason for it. No legitimate reason for disguising the URL either.