sweet, thanks guys. Mark, thanks for the knowledge. Michel, thanks for the pointer. Unfortunately I work for a Public funded organisation so any solution has to be tried-tested-certified and bullet-proof (Why we are with Microsoft is anyones guess....sorry Bill)
evtools do seem to have some good solutions, but I need something with a good customer base as we are thinking of implementing a multi-tiered vaulting solution. So ALL mail gets vaulted after 30 days for retention of 12 months, anything that was sent to certain people would then get moved to a longer term vault or anything legal moved to a 7 year vault, etc,etc (We still need to battle out the structure, but that will be decided once the project has been tested on some non-critical mailboxes, then documented, then approved and so on)
Again thanks to you both for your help and advice