1. Spam emitted by a reputable, mainstream company (as opposed to
fly-by-night Viagra oeddlers and the like). Sometime this happens in
honest ignorance, but the reputation danage can take years to live
down.
2. Occasionally used for a big-time spammer, with its own {fat pipe},
their own mailservers, and a {pink contract}. Almost impossible to
get shut down.
[glossary]