My question has to do with Exchange re-using whitespace. Let's say we have a 500 Gb Exchange database and we remove 200 Gb of data from it (delete mailboxes). At this point, the database size will still show 500 Gb but in fact there will only be 300 Gb of data in it.
Now let's say that we add 100 Gb of data. Will the 100 Gb of data fill some of the 200 Gb of whitespace or will it take an additional 100 Gb of external disk space?