Exchange Server 5.5 Internet Mail Service

[earles]

I'm using Exchange 5.5 to send and recieve internet mail. We have a cable modem.

My question is this:
I'm seeing alot of outbound mail in the que with <> as the originator. It never goes out but how does it get in there? When I first set up Exchange we had an Open Relay. I closed this by setting Routing Restrictions to Host and Clients that successfully authenticate. Is there something else I need to do?

Thanks for any help!