This is similar to my last script to count the number of servers operating the web clusters at sitefinder.verisign.com. It works the same way. The SMTP daemon gives its machine name in the banner. By keeping track of what servers it sees, this script determines how many there are.

When it runs, "+" means it saw a new server, "." means it saw a server again, and SIGINT (ctrl-c) makes it stop and print its report.

At the time of writing this script, I was seeing 3 servers on the West Coast and 4 on the East Coast.

Their SMTP rejector is _so_ broken. This is really the most unclued RFC breaking peice of code I have ever seen put in such a place of importance. Here is an easy way to display how stupid this peice of code is: Telnet to the SMTP Rejector (telnet sitefinder-idn.verisign.com 25), after it connects and you see the banner, just hit enter five times..

[ Update: This script no longer works.. They have replaced that SMTP server. I have not taken a close look at the new one yet. ]