Our family / family business has run, with increasing formality, email servers in various flavours since the mid-90's. These servers have processed messages including everything from lots (like really lots -- in the tens of thousands at least) of family pictures to (no doubt) lots of personal email of the many dozens of staff who have worked with us over the years. In general, the server settings have always been set to "retain everything", including full Exchange journalling, because there was no way to delete things without risking losing some important pictures someone sent to someone else.
I'm not too worried about the business activity traffic, because anything recent is well replicated in many other places -- primarily in various cached Outlook data files. But where family members threw away their old machines, the only copies of these important things are in the server journals we have archived. Is there some solution that can rationalize these millions of messages into some sort of structure?
In addition, I presume that this can only be done for individuals who actually want old items to be retrieved from the archives, as anyone else would be protected by privacy rights.