I've personally seen them blackhole a customer ip and never contact
them. The excuse was that, normally, their customers can't get the mail
because it's a mailserver that gets blacklisted. I'm not sure that it's
an excuse. I don't even mind that they blackholed a security problem.
It's the lack of contact in association with the action that I consider
bad customer service.
Eric Krichbaum, Chief Engineer
Citynet