[Dimensio]

If your determination of Yahoo's involvement came from a "From" address ending in @Yahoo.com, then they may well have been innocent. The "From" header in e-mail is incredibly easy to forge, and yahoo.com addresses are often chosen. The only real way to determine the source of a message is through the Received: header, which lists the IP address of at least the last mailserver from which the message originated.

On the other hand, if the spammer claimed a contact e-mail address with Yahoo, then Yahoo is responsible for killing the account of the spammer. Unfortunately, it's not yet legal to kill the spammer himself.

[agrace]

Ok, that explains a lot. As far as I can recall, it was just the "from" address that was Yahoo. Thanks very much for the info!