Network protection should not rely on a single magic bullet solution, but on layers of overlapping security.  Mail should go through a couple of virus checkers and spam filters before it ever hits your inbox.  A firewall keeps unwanted network traffic out and blocks unexpected outgoing traffic.  Layered firewalls -- at the Internet connection and on each computer -- provide better security.  Managing outgoing traffic via DNS filtering is another layer of protection for both home and corporate networks.
 

I have an ongoing problem with network access from my desktop computer.  There's no way to pull a network cable to it, so I've been using a wireless network card.  That should be OK, but I often get degraded network performance if the microwave is on and, from time to time, the network card loses touch with the router.  It happens so frequently, in fact, that I run a script every two minutes that pings the router and, if it can't be found, restarts the network card.  An article in the New York Times suggests going back to a wire -- the power line.