I set up a Debian Sarge machine with Exim4 for a neighbor. We have the same comcast cable internet connections and identical linksys routers. I configured Exim to use comcast's smart host with base-config and set up smtp authentication and everything worked fine at my house. I moved the system and hooked it up at my neighbors house, and now I cannot send email messages. The setup is identical, as far as I can tell - same internet connection, same router configuration, same system - just a different location. I re-ran base-config and restarted Exim but still no luck. Any ideas?