Hi rfa72,
you've been pointed in the right direction by ls-al.
- Locate the pc which hosts the smartcache for the corrupted mailbox
- Detach it from the network (unplug the cable) just to be sure it won't connect to the scalix server
- Open outlook
- Try to export mailbox data into a pst file
However just keep in mind that if your smartcache was set up to sync only headers (and bodies on demand) than you smartcache will be quite uncomplete.
Good luck.