Hi, I'm exporting mailboxes of old users to pst files because we want to remove the mailboxes from the exchange server. The funny thing is that some pst files are much bigger than the mailboxes. For example: Mailbox: approx. 300MB PST: approx. 400MB Mailbox: approx. 100MB PST: approx. 400MB I also exported one mailbox 3 times: 1st size of pst: 466.257KB 2nd size of pst: 426.081KB 3rd size of pst: 426.081KB Very odd, isn't it?

is the mailbox size inclusive of dumpsterThiyagu | MCTS/MCITP - Exchange 2007 | MCSE 2003[Messaging] | http://www.myExchangeWorld.com. This posting is provided "AS IS" with no warranties, and confers no rights.

Due to the way that the PST file works, a bloat of three times the size of the data in Exchange is not unusual. Therefore the numbers you have posted are not unusual at all. PST files work in an odd way, storing the data in all three formats. Then you have the encoding overheads and other things within the file. Simon.Simon Butler, Exchange MVP. http://blog.sembee.co.uk , http://exbpa.com/

Hi Mav2000ger, I just done some test, the result is very familiar with your first situation, and I went through some documents and have not found the useful information. So I think maybe the PST file has its own mechanism for works. Best regards, Yang