here it is: http://www.enkive.org/ I'd really like to see some tutorial for email archiving and it seems for an email archive to be legally binding you must do more than simply bcc every mail and this software is open source and seems to comply to the general laws that require an email archive. Preferably for Debian ;-) anyone else interested?
Yes, I am looking into this as well - tho would like to use a separate physical server for Enkive. PM sent.