I don't think the sysadms here would have an infected machine sending email worms outside their network at least not for an extended period of time. ;D

I think doing this individually and manually is perfectly acceptable. You connect to others hardware, ports and services constantly while using your PC. The worm itself was written with remote removal capabilities. You are using the software within the range of its intended purpose.

Now if you automate this process such as nachia, which also installed malware to scan for infected machines, you've gone to far.