What's in Your Junk Mail Folder?

Everytime I get a challege response from someone using the RiskFreeMail.com service, the email winds up in my Outlook Junk E-mail folder. No other challege response service has this problem. Is it a statement about their implementation?

Frankly, I think challenge response is getting silly anyway. In order to send some people email messages, I send the message and then have to type another message in a form to tell them why I sent the message.

Coming soon to spam solutions everywhere, the challenge to the response to the challenge. I can't wait.