With no firewall rule to open TCP port 25 dnscheck.net reports a timeout when connecting on port 25. If I add a firewall rule to open TCP port 25 checkdns.net reports that the connection was refused.

Naturally I ass-u-me'd this to be a mass infection of Slammer. <BR><BR>I routinely scan our domain (the library) for nasty open ports, and so far have only found one case of port 1434 being active.