Is the Overnight Envelope Anti-Green?

At the recent Fortune Brainstorm: Green conference, the subject of the famous FedEx overnight envelope came up. One of my fellow panelists said he was surprised to still see those envelopes, implying that the contents could easily be transmitted electronically, and that somehow this service was environmentally "wasteful." He made me realize how easy it is for people to make the wrong assumptions or hold on to outdated ones.