In my basic experience, ORDB is pretty good about removing sites within a day or so of a problem being resolved. This, however, requires sysadmins who understand how the mail system works and who have the skill to fix it. This is almost certainly absent at Sprint if my experiences with them are any judge.
These days the most common way of getting an open relay is to have a Windows machine that is infected with any one of a number of viruses that install them. But, with a machine that is intended to relay messages to an external network, there are a large number of ways that an incompetent admin can hose things up. I would not be surprised if nobody at Sprint DOES understand the problem. --scott
"C'est un Nagra. C'est suisse, et tres, tres precis."