Dealing with Abusive E-Mail?

sheetzam asks: "I am the manager of the mail system for a reasonable (3000 employees) sized media company. Recently a website has decided to post the e-mail addresses of a few of our employees, and suggest readers send those people abuse. We know we have no legal recourse for removing the e-mail addresses from the offending web site. We can't filter the abusive e-mail based on header information because it is coming from many places. Our only choice seems to be to change the person's e-mail address. If this were an abusive phone call, we'd know exactly how to handle it. But e-mail is quite different. How are others dealing with this?"