i've moved roughly 2.5GB out of Public Folders yesterday, finishing about an hour before database maintenance commenced.
At the end of the online defrag, the event log entry id 1221 states:
The database "Second Storage Group\Public Folder Database" has 23 megabytes of free space after online defragmentation has terminated.
The deleted items retention is set to 0 days. I was expecting the "free space" value to be roughly around the 2.5GB mark, reflecting the emails that had been removed.
Why only 23MB? Is there a cache I have to clear etc?