How was 100 million spams sent out from my reseller account?

Had a client send out massive spam and wonder how he did it?

[lizzie]

I had a small reseller account. A client sent out 100 million spams from it and I had problems. How is this done? Does he use squirrelmail or what? What does it show as a return address? How do people send out millions of spams? What software program would hold that much? Just curious.

[jamesa]

If your server has sendmail or an equivalent and can run cgi/server-side scripts then they have everything they need.