I remember Urs arguing for this at TGIF quite some time ago. He said legal costs were increasing exponentially while the value of old email was only linear, which was unsustainable.
One outcome of this was to wipe a number of ongoing scientific discussions I was having with external collaborators. I'm used to people having the last 30 years of mail on hand to be able to carry out extremely long, complex projects.
replies(3):