What does compacting of a Microsoft Outlook or Microsoft Outlook Express file actually do? In the case of Microsoft Outlook the compacting takes place in what is known as the PST file. Consider that until we compact the PST file so as to make room for more messages and other Microsoft Outlook features all of our messages and other data remain in the file.
The messages themselves are marked as deleted but just as with files placed into the Windows recycle bin the data remains and it is easy to recover deleted emails using the Remo Software Outlook recovery tool. To recover accidentally deleted emails using this tool simply direct the software to scan your PST file and it will create a list of all recently deleted emails. However when you direct Microsoft Outlook to compact the PST file the program rewrites all of the database information in new locations. This rewrite process essentially scrambles and erases all underlying data.