This Crimson article about professors who do not use e-mail seemed like normal fare until I read this paragraph:

Orchard Professor in the History of Landscape John R. Stilgoe doesn?t use his Harvard address either, but for security reasons. Because e-mails travel through Harvard?s local area network (LAN), messages could end up in the hands of someone other than the intended recipient, Stilgoe said, pointing out that even intended recipients can forward messages to a third-party without permission.

I will assume that Stilgoe was misquoted about the LAN, and was concerned about his e-mail traveling through networks in general. While this is a valid concern, it is also possible (and probably easier) to read others' paper mail. Also, "forwarding" messages did not begin with the birth of e-mail, since paper messages can be easily passed from person to person. Stilgoe's fear might be lessened if he chose to encrypt his messages - a task easily accomplished if he was using e-mail.
?Outside of a couple of students in applied math, I have yet to meet a Harvard undergraduate who knows how [Harvard?s e-mail system] works,? Stilgoe said.

Despite Stilgoe's obvious qualifications on determining whether Harvard undergraduates understand e-mail, perhaps he would meet more undergraduates if he used an e-mail address.