Exchange 2000 Server Enterprisedatabase size

Hi,

I have a question about the database size of the Exchange server 2000 Enterprise. I have got hdd of 68.3GB. MDBdata size is 49GB. When i am exporting mailstore data it is 88 GB. Can anyone tell me why this is happening. My hdd has capacity of 68.3 GB. We are storing transction log on seperate HDD which is of 80 GB.

What is the best way to analyse exchange database size.

Thanks & Regards
Siddhpal Patel