I have Thunderbird set to download my inbox for offline usage and I periodically delete all mails from my account and store encrypted archives in safe offline locations. Sometimes I will email important mails back to my gmail in encrypted format so I can still access them from the outside wherever I have gpg.
I think with things like the HBGary hack this is only becoming more and more vital, and it's really not that hard to handle since Thunderbird already saves all my mail locally. You just move it from the IMAP folder to a local folder, export that local folder (there's a great TB extension called ImportExport that gives you lots of options here), encrypt it and upload it to multiple backup sites.
What would have happened if HBGary had a policy like this? A lot of embarrassment would have been saved, even if not all of it (much more would have been saved by sending mails encrypted in the first place).
I think with things like the HBGary hack this is only becoming more and more vital, and it's really not that hard to handle since Thunderbird already saves all my mail locally. You just move it from the IMAP folder to a local folder, export that local folder (there's a great TB extension called ImportExport that gives you lots of options here), encrypt it and upload it to multiple backup sites.
What would have happened if HBGary had a policy like this? A lot of embarrassment would have been saved, even if not all of it (much more would have been saved by sending mails encrypted in the first place).