Do you keep old e-mail?
chops: I use a separate email account for newsgroup subscriptions, but beyond that, I have every email I've ever sent or received for the past 7 years or so.  Before gmail, I have my old thunderbird email files zipped up and archived incase I ever need them (doubtful), but it's there.  And most of those would be business related for a job I haven't had for 5 years.But yes, I keep everything.