I need to archive and then recombine some email data files for a client. I am noticing a large size difference between the current OST files they are using and the PST files I create if I do an export from those accounts. (eg 5G for OST and 2.4G for resulting PST). Is this large a size difference something to be concerned about? The client has made a complete mess of the data by somehow partially importing other data files and using more than one account in the same profile. I am trying to sort this out and need to export piecemeal from all involved datafiles to try and recombine thiings into one file for archiving. I am concerned that I may be missing something if I just assume the small PST file mirrors the parent OST file given the size difference.