Only problem was that the customer hadn't subscribed to and didn't have access to the eDiscovery tools he wanted me to use and I'm not sure what good a 'hold' would do days after the fact? Kind of hard to use tools that are not available to you. Two days later I received an email from 'support' with instructions from the engineer to use eDiscovery tools to put a hold on the mailbox and to see what happened to the folder. It took them a few hours to get back to me initially but after a quick few questions and connecting to the computer so he could 'point' out where to look he told me they would have to assign an engineer to look into it and get back to me. He had a few missing items that would cause him serious pain if we couldn't recover them so I contacted support. I looked everywhere for it and could find no sign of the folder or its contents in any folder, deleted items or in recovering deleted items.

I figured the same thing - he accidentally moved or deleted etc. A folder in his mailbox just 'went away'.