I have set up the bandwith sensor for my router through SNMP. That only shows usage though. Is there a sensor that will actually show me the email headers going through the router. I believe a computer in my network has been spamming email because we got blacklisted by three services. If this isn't possible is there a way to monitor the network for excessive email spam? I run a windows environment with a Netgear router hooked up to a cable modem. I cannot simply shut down port 25 because I have a lot of Outlook users who use that port.