Which is the most valuable function? "e-mail threading, definitely," Palumbo says. "In a decision, that could be made in 20 or 30 e-mails going back and forth, and each person on the distribution list has a copy. If you have to have a lawyer open each of those instances, the cash register will be running a long time."

E-mail threading lets Palumbo get a single chain that contains all the relevant information, and delete the rest, not to mention the rest of the mailboxes and other detritus.

Typically, using careful filtering and keywords, Palumbo can get a 100GB file down closer to 5GB.

Lawyers still have go manually through the final 5GB, but the bill is a lot smaller than it would be otherwise.